UNIT 3 .docx

1 | GB 513 Unit 3 Success Guide v.6.13.17
UNIT 3 SUCCESS GUIDE
This unit is the other “most difficult” one. Hypothesis testing
has two parts: setting-up
the hypotheses and calculating the critical values to determine
results. They both
pose difficulty for a lot of students. The seminar will be on the
first and the recorded
lecture will be on the second. You need to make sure you
understand both,
otherwise you will not be able to get to the right conclusions.
1. As always, start by reading the chapters and studying the
solved examples.
2. Watch the lecture video in document sharing. It focuses on
why we do
hypothesis testing, how to do it with Excel and solves two
sample problems.
3. Watch this from Khan Academy:
https://www.khanacademy.org/math/statistics-
probability/significance-
tests-one-sample/tests-about-population-mean/v/hypothesis-
testing-and-p-

values
This one talks more about how to write the null and alternative
hypotheses
(which a lot of students get wrong) and also solves the problem
using
formulas.
4. Watch the sample problem solutions in Course Resources.
5. If you still want more videos, search YouTube for
“hypothesis testing.” Several
introductory level videos are available, such as
https://www.youtube.com/watch?v=HmMjS88eSVE and
https://www.youtube.com/watch?v=0zZYBALbZgg
Email your instructor if you find any of these links to be
broken.
Avoid these mistakes!
GENERAL NOTES
RESOURCES
COMMON MISTAKES IN THE ASSIGNMENT

probability/significance-tests-one-sample/tests-about-
population-mean/v/hypothesis-testing-and-p-values
http://www.youtube.com/watch?v=HmMjS88eSVE
http://www.youtube.com/watch?v=0zZYBALbZgg
reversed, or
get them completely wrong.
This is correct:
“null hypothesis: there is no difference between the average
salary for
group 1 and the average salary of group 2.” This is not
sufficient: “ho:
x1=x2”

and base
their determination on which one is greater, rather than properly
doing a
hypothesis test.
write out
what the conclusion is. This is correct: “We therefore reject the
null
hypothesis, which means we conclude that there is a difference
between
the average salaries of the two groups.” This is not sufficient:
“reject null.”
idea which
metric to use in order to make a conclusion.
The questions below are very similar to what you need to solve
in the assignment.
Some, but not all, of these solutions were demonstrated on
video and recorded
for the live binder by the math tutors.
SAMPLE PROBLEM 1 FOR ASSIGNMENT PROBLEM 4

A hole-punch machine is set to punch a hole 1.84 centimeters in
diameter in a
strip of sheet metal in a manufacturing process. The strip of
metal is then creased
and sent on to the next phase of production, where a metal rod
is slipped
through the hole. It is important that the hole be punched to the
specified
diameter of 1.84 cm. To test punching accuracy, technicians
have randomly
sampled 12 punched holes and measured the diameters. The data
(in
centimeters) follow. Use an alpha of .10 to determine whether
the holes are being
punched an average of 1.84 centimeters.
Assume the punched holes are normally distributed in the
population.
1.81 1.89 1.86 1.83
1.85 1.82 1.87 1.85
1.84 1.86 1.88 1.85
SAMPLE PROBLEMS AND SOLUTIONS
SOLUTION
n = 12 x = 1.85083 s = .02353 df = 12 -

n
.02353
12
n
.1895
20
The following data (in pounds), which were selected randomly
from a normally
distributed population of values, represent measurements of a
machine part that

is supposed to weigh, on average, 8.3 pounds.
8.1 8.4 8.3 8.2 8.5 8.6 8.4 8.3 8.4 8.2
8.8 8.2 8.2 8.3 8.1 8.3 8.4 8.5 8.5 8.7
Use these data and alpha =0.01 to test the hypothesis that the
parts average 8.3
pounds.
H0: µ = 1.84
For a two-
Since t = 1.59 < t11,.05 = 1.796,
The decision is to fail to reject the null hypothesis
SOLUTION
n = 20 x = 8.37
Ho: µ = 8.3
s = .1895 df = 20-

For two-
Observed t = 1.65 < t.005,19 = 2.861
The decision is to Fail to reject the null hypothesis
p̂
n
(.48)(.52)
380
p̂
n

(.31)(.69)
600
The Independent Insurance Agents of America conducted a
survey of insurance
consumers and discovered that 48% of them always reread their
insurance
policies, 29% sometimes do, 16% rarely do, and 7% never do.
Suppose a large
insurance company invests considerable time and money in
rewriting policies so
that they will be more attractive and easy to read and
understand. After using
the new policies for a year, company managers want to
determine whether
rewriting the policies significantly changed the proportion of
policyholders who
always reread their insurance policy. They contact 380 of the
company’s
insurance consumers who purchased a policy in the past year
and ask them
whether they always reread their insurance policies. One
hundred and sixty-four
respond that they do. Use a 1% level of significance to test the
hypothesis.

A survey was undertaken by Bruskin/Goldring Research for
Quicken to determine
how people plan to meet their financial goals in the next year.
Respondents were
allowed to select more than one way to meet their goals. Thirty-
one percent said
that they were using a financial planner to help them meet their
goals. Twenty-
four percent were using family/friends to help them meet their
financial goals
followed by broker/accountant (19%), computer software (17%),
and books
(14%). Suppose another researcher takes a similar survey of 600
people to test
these results. If 200 people respond that they are going to use a
financial planner
to help them meet their goals, is this proportion enough
evidence to reject the
31% figure generated in the Bruskin/Goldring survey using
If 158 respond that they are going to use family/friends to help
them meet their

financial goals, is this result enough evidence to declare that the
proportion is
significantly higher than Bruskin/Goldring’s figure of .24 if
alpha = 0.05?
SOLUTION
Ho: p = .48
= .4316
n 380
z = = -1.89
Since the observed z = -1.89 is greater than z.005= -2.575, the
decision is to
fail to reject the null hypothesis. There is not enough evidence
to declare that
the proportion is any different than .48.

(.24)(.76)
600
SAMPLE PROBLEM FOR ASSIGNMENT PROBLEM 6
Since the Assignment requires you to use the data analysis tool
pack for this
problem, the best way to prepare is to watch the lecture video,
which gives two
examples, both solved using Excel.
SOLUTION
Ho: p = .31
= .3333

z = = 1.23
Since the observed z = 1.23 is less than z.005= 1.645, the
decision is to fail to reject
the null hypothesis. There is not enough evidence to declare that
the proportion
is any different than .31.
Ho: p = .24
Ha: p > .24
n 600
Since the observed z = 1.34 is less than z.05= 1.645, the
decision is to fail to reject
the null hypothesis. There is not enough evidence to declare
that the
proportion is less than .24.
Resources

Khan, S. (2017). Hypothesis testing and p-values. Retrieved
from
probability/significance-tests-one-
sample/tests-about-population-mean/v/hypothesis-testing-and-p-
values
Perdiscotv. (2010, January 14). Introductory statistics – Chapter
8: Hypothesis testing.
Retrieved from
https://www.youtube.com/watch?v=HmMjS88eSVE
Statistics learning centre. (2011, December 5). Hypothesis tests,
p-value – Statistics help.
Retrieved from
https://www.youtube.com/watch?v=0zZYBALbZgg
https://www.youtube.com/watch?v=HmMjS88eSVE

DSDM Case Study
Improving Outcomes through
Agile Project Management
General Dynamics
United Kingdom Limited
D E & S
Defence Equipment & Support
www.dsdm.org
Timothy Fadek/Polaris/eyevine
www.generaldynamics.uk.com
TRUSTED TO DELIVER
Application of the
Dynamic Systems Development Method
in a Complex Project Environment
A General Dynamics United Kingdom Limited
White Paper
Helping clear the ‘fog of war’
Improving outcomes through agile

Project Management
The Combat Identification Server (CIdS) Technology
Demonstrator
Project (TDP) has been delivered to time, quality and budget
using the
Dynamic Systems Development Method (DSDM®).
This trial application of this method
by the Ministry of Defence (MoD)
Defence Equipment and Support
(DE&S) has:
l demonstrated the suitability of
the application to a DE&S project
l provided lessons for the future
application of DSDM
l shown the effectiveness of the
method in achievement of
delivery to time, quality and
budget.
The CIdS TDP has been funded by
the MoD DE&S Tactical Datalinks
Delivery Team (TDL DT) and
delivered by an industry consortium
led by General Dynamics United
Kingdom Limited. CIdS is a complex
system/software project. The
objective is to help clear ‘the fog of
war’ by providing a picture in the
cockpit of an aircraft of the position

of nearby friendly forces on the
ground.
Introduction
The deployment
of CIdS will
reduce the
probability of
mistaken identity in
the heat of battle
The use of DSDM was a bold move,
but the project has rapidly delivered
successful outcomes for all
involved. In the current economic
environment, delivering solutions
within budget is top priority. Could
this approach be the future for
project management in the defence
sector?
Traditional approach DSDM approach
Traditionally project management in the defence sector has
focused on
meeting technical requirements, sometimes at the expense of
project
duration and cost. In a DSDM project, the performance
requirements are
expressed as Must, Should, Could and Won’t (this time) or
‘MoSCoW’. In
the DSDM model trading out requirements provides the

flexibility to
ensure on-time and on-cost delivery of an acceptable and fit for
purpose
solution rather than a perfect one.
In practice, the development of the
CIdS capability was divided into
increments. Dividing the CIdS
project into increments provided
checkpoints at which capability
could be demonstrated.
Each of these increments was
divided into timeboxes. If, in the
delivery of any timebox, it was
apparent that there was risk to the
achievement of the Must
requirements, effort was expected
to be redeployed from the tradeable
Should and Could requirements to
assure delivery of Must
requirements.
CIdS TDP – Applying DSDM
If it became apparent that the Must
requirements were in jeopardy, then
the timebox and potentially the
whole project could have been
stopped or re-planned; extension of
a timebox is not permissible. This
discipline is key in the ‘fail early’
principal of DSDM.
DSDM inverts the normal project management paradigm

FIXED
VARIABLE
Features
Features
Quality?
Quality
Time Cost
Time Cost
The effectiveness of DSDM
has been successfully
trialled and demonstrated
in the CIdS TDP
Traditionally a financial contingency
is held, to be called upon if
difficulties are encountered in
delivering the required project
outputs. DSDM renders financial
contingency redundant. Instead, the
CIdS project requirements were
categorised using the MoSCoW
approach. Through a trading process
during project execution, this
technique enabled a few Should and
Could requirements to be removed
from the project solution to prevent

potential cost and schedule overrun,
without any customer penalties
being incurred.
DSDM is typically applied to
software dominated internal change
projects within the Information
Technology sector. As such, the
CIdS project was also seen as
breaking new ground commercially
through the application of DSDM on
a project involving a consortium of
companies.
Business and
Commercial
From a business perspective the
use of DSDM required a
significant change in approach to
the project.
Negotiation
As a result of the unique method
of delivering the CIDS project,
negotiations had to overcome the
impacts of using DSDM.
Thankfully we were all learning
together!
The TDL DT had an initial concern
that the consortium would abandon
Should and Could requirements at
the first opportunity and an

incentivisation mechanism was
sought. However, this approach
contradicted DSDM principles
where cost – and hence price – is
fixed, with requirement trading
offering the project contingency.
During contract negotiation this
incentivisation position was relaxed
as the TDL DT recognised that the
consortium would aim to maximise
the delivered capability.
One aspect that required ongoing
negotiation through the project was
the payment plan. Once the project
started, it became apparent that the
detailed project schedule that was
developed during the initial stages
of the project no longer fitted the
payment plan that had been agreed
prior to contract award. By taking a
pragmatic and flexible approach, and
recognising that this is the nature of
DSDM, TDL DT and industry were
able to align programme and
payments.
Instead of including a detailed
schedule of the project delivery with
the bid submission, expert advice
was that this process should be
performed jointly with the TDL DT
after contract award as part of the
Foundation phase. This was not, it
was advised later, what the TDL DT
wanted to hear!

Before the team launched into detail
it needed to put the project into
context by focusing on the
fundamental project objectives. This
was achieved through the
collaborative development of a
Single Statement of User Need
which stated:
“Report blue force track
information to authorised
requesting entities on demand in
the Close Air Support (CAS)
mission.”
As the planning progressed, so did
the collective understanding of the
technique.
A key objective of the DSDM
approach is to progressively reduce
risk through incrementally delivering
a solution. As such, establishing
how the technical solution would be
elaborated within the DSDM
framework was also a key part of
the planning the overall strategy for
delivery of the CIdS project.
Planning the
strategy
The project delivery strategy
started with the TDL DT requiring
the use of DSDM as the project

delivery method. With theoretical,
but little practical experience of
DSDM, the consortium used an
external DSDM expert to guide us
through the bid phase.
The initial stages of the project
required a fair degree of
tolerance to lack of clarity!
Techniques
The selection of DSDM for the
CIsS TDP was motivated by the
TDL DT’s objective to
demonstrate that complex
military technologies could be
delivered without delay or cost
overrun.
Using DSDM, the CIdS project
comprised three distinct phases.
The Foundation Phase developed
the requirements, technical design,
and also planned in detail the
subsequent Exploration/Engineering
Phase where the CIdS solution was
incrementally developed through a
series of timeboxes where
MoSCoW’d requirements were
logically grouped. These timeboxes
constrained the implementation to
time, cost and quality. The final

Deployment Phase demonstrated
the CIdS solution to end users.
Project success was built
on the outline planning
developed in the
Foundation Phase.
Throughout the CIdS project, focus
was maintained on control and
metrics regarding achivements
within each timebox. Whilst all
project timeboxes were planned
ahead in outline, as individual
timeboxes ended, the performance
within that timebox enabled the
detailed planning of the next
timebox.
This incremental and iterative
development approach where
achievement informs ongoing plans
was at the heart of the project.
Organisation
and Governance
Using a facilitated workshop as
part of the Foundation phase the
CIdS project organisation was
developed resulting in consensus
and buy in from the project
outset.

Nominated individuals were
assigned to the roles detailed in the
structure which have defined
responsibilities. The CIdS project
team comprised individuals from
TDL DT, General Dynamics UK
(industry consortium lead),
consortium partners Rockwell
Collins UK and Qinetiq as well as
3SDL, the TDL DT’s specialist
technical advisor. One clear and
highly beneficial outcome of using
the DSDM ‘Space Alien’ structure
was that it removed any hierarchy
associated with the contractual
relationships, resulting in a truly
integrated team.
Empowerment of the
individuals allocated to the
roles was a pre-requisite
Reviewing structures were put in
place to ensure appropriate
governance of the project,
comprising monthly project reviews
with the General Dynamics UK
Programme Director and gate
reviews at the end of each phase
and increment with representation
from both industry and the TDL DT.
CIdS TDP DSDM Organisation Chart – The ‘Space Alien’

Personnel
Management
Requiring the implementation of
a new project management
method required people with a
pragmatic, flexible and open
minded approach. For all involved
the project offered a great
personal development
opportunity.
Selection of the right personnel to
lead and work on the project was
critical. DSDM requires people with
the ability to work effectively within
collaborative teams and a tolerance
of ambiguity. This was not a project
for task focused left-brained project
managers!
Equally the assignment of the
technical co-ordinator role was
pivotal. The role has required a
combination of technical domain
knowledge, foresight and leadership
to ensure the technical solution
achieved its requirements.
The CIdS project, with its ground
breaking use of DSDM provided
excellent personal, as well as
organisation, learning experience.

Traditionally there is reticence to
share ‘warts and all’ information
between partners and/or customer.
As the team relationship developed,
aided by significant periods of co-
located working, an open and no
surprises culture of communication
developed. A clear no blame
mandate was established to
promote open and honest
communication. Where frustrations
between groups did develop they
were effectively addressed to
prevent any damage to the day to
day working relationships.
Other communication aids were
also developed by the team.
Through timebox management
worksheets, clear communication of
requirements to be implemented,
associated estimates and the
allocated of resource were provided.
Daily progress of timeboxes was
reviewed by team leads such that
exceptions were managed as they
arose instead of later.
A key facilitator of effective
communication was an electronic
Shared Working Environment,
supported by email, and
telephone/video conferencing.
Communication

Continuous, clear and effective
communication has been a
mantra for the CIdS project.
Personally, the CIdS project
was a great development
experience
Gavin Green – CIdS Technical Coordinator
CIdS project success was
underpinned by the Foundation
phase outputs and the associated
facilitated workshops. Through the
foundation phase the project
developed the plans collaboratively
ensuring consensus. Strong
leadership however ensured that
there was no management by
committee that could have resulted
in indecision and deviation from the
project objectives. Establishing the
detailed technical requirement and
partitioning these into a logical
development strategy was
challenging but the detailing of the
timeboxes was eventually achieved.
Emphasis through the Exploration
and Engineering phase was to
ensure that the project objectives
were delivered. Managing schedule
adherence was relatively
straightforward since it was bound

by the timeboxing. However metrics
were devised to monitor
performance against technical
outcomes to help inform the
planning of subsequent timeboxes.
These also addressed concerns that
incomplete timeboxed requirements
could be deferred into later
timeboxes, potentially resulting in a
bow wave resulting in a technical
solution only meeting the ‘Must’
requirements.
Executing the
Strategy
From the outset, the CIdS project
sought to differentiate itself by
reshaping the traditional MoD –
Industry relationship.
The detailing of the increments
and timeboxes caused some
nervousness, but once completed
resulted in what the TDL DT called
‘the Eureka moment!’
CIDS TDP – Success Factors
Coaching and
Mentoring
DSDM as project delivery
technique was new to everybody

and meant that we all learnt
together.
Expert DSDM input during the
project bid phase brought
confidence that the planned
approach to the delivery of CIdS
was the right one. As a result, the
industry consortium was able to
contribute from an informed
perspective during the crucial
Foundation Phase workshops.
Throughout it was important to
ensure that all involved maintained
the same common view of what
DSDM meant for the CIdS project.
Whilst there was early confusion
that DSDM was a substitute for
engineering process, through team
mentoring a common understanding
was soon established.
Teamwork
Successful delivery of the CIdS
project was achieved through the
behaviours and motivations of
the people involved – the
teamwork.
A new project delivery method
required key personnel with a
pragmatic, flexible and open minded
approach, coupled with a tolerance
for ambiguity and excellent

teambuilding skills.
The teamwork has come about
through the desire to collaborate, to
learn together, communicate and
build the necessary relationships to
successfully deliver the CIdS
project.
Any stresses in the team dynamic
have been recognised and dealt
with early, and before they become
issues.
Teamwork on
CIdS has been
underpinned by
having the right
personalities in
the key project
roles
Conflict
Management
Through the highly collaborative
and open team approach, with a
no surprises culture, conflict has
been kept to a minimum.
As in most projects there have been
stress points during the project, but
because of the team relationships,
these have been anticipated and
quickly resolved.

In traditional projects with their
fixation on the achievement of all
technical requirements, a defensive
We left conflict to
those better qualified!
posture can often arise if problems
in achieving those requirements
emerge. The CIdS project, through
the highly collaborative approach,
and safety net of requirements
contingency resulted in a far more
open environment where good and
bad issues were openly discussed.
Risk
Management
CIdS benefitted from a risk
management strategy that used
an incremental development
approach in which high risk
requirements were tackled early,
with requirements flexibility
protecting on-cost,
on-schedule, to quality delivery.
A joint risk register was established
to inform timebox management and
ongoing engineering development,
but not to identify any required
financial contingency. Instead of
holding financial contingency, any

additional funds that were required
to ensure delivery of ‘must have’
requirements were drawn from the
budget associated with delivery of
lesser priority tradable
requirements.
Key benefits that resulted from the
way in which the CIdS project was
managed include:
l More believable plans, schedules
and budgets, and likelihood of
adherence were a fundamental
outcome as a result of the DSDM
approach with its fixed cost and
time approach.
l Using DSDM led to a contract
which eliminated financial
contingency, delivery maximum
possible capability for the funds
available.
l The timeboxing approach resulted
in multiple decision points at the
end of each timebox, and each
increment, at which alternative
ways forward were compared.
l The cost base for the project was
reduced as no financial
contingency was needed.
l Through the Single Statement of
User Need a common vision of

the project objectives was
collaboratively developed.
l With short timebox spans, risk
assessment has been aided by
the increased focus that resulted.
l Greater risk taking was enabled
as by principle the project could
not go over budget, or slip
schedule. This allowed desirable
but higher risk requirements to
be included as Should or Could
requirements without fear of
penalty to the project. As a result
greater capability has been
delivered to the end-user for the
same money than would
otherwise have been possible.
With MoD funds under continual
pressure, successfully
demonstrating incremental
capability was also way of reducing
the risk of project cancellation by
keeping stakeholders engaged and
supportive of the CIdS project.
The net effect
was that
100 per cent of the
project budget was
dedicated to the
delivery of
capability

CIDS TDP – Summary
The CIdS project has been a learning experience for all
involved, and has
demonstrated that the MoD and industry can employ radical
project
management techniques to successfully deliver a technically
complex
project.
Through using DSDM on the
project, the traditional
customer/supplier and prime
contractor/subcontractor divides
have been bridged to form what
truly has been an integrated project
team. The one for all, all for one
ethos has prevailed throughout,
resulting in a team that focused on
delivering on the project objectives
rather than what is best for
individual organisations.
Whilst DSDM has been central to
the delivery of the project, it is not a
panacea. The CIdS project has
ultimately been successful because
of the team – their professionalism,
their technical capabilities and their
commitment to the principles of
DSDM.
The use of DSDM was a bold move,

but the CIDS project has delivered
successful outcomes for all
involved. In the current economic
environment, delivering acceptable
solutions on time and at a fixed cost
is surely a priority for the MoD. The
success of the CIdS project may
have provided pointers for the future
of project management in the
defence sector.
The use of the Dynamic Systems
Development Method has been
key to the success of the Combat
Identification Server TDP: agile project
management techniques, the close
involvement of stakeholders
throughout, including interim
demonstrations, and a constant focus
on the deliverables have ensured that
the final product will truly hit the
mark. This methodology has clearly
worked extremely well and I would
hope to see lessons from this project
applied to future projects.
Major Fiona Galbraith, MoD sponsor.
Commendation
DSDM is a registered trademark of
Dynamics Systems Development
Method Limited

www.generaldynamics.uk.com
GDUK878 06/10
© October 2010 General Dynamics United Kingdom Limited
The information contained in this publication is supplied by
General Dynamics UK
Limited (GDUK). It does not form part of any contract for the
purchase of any product
or service described in this publication. Although GDUK makes
every effort to verify
the accuracy of the information contained in this publication,
the company accepts no
responsibility for any defect or error in this publication, or in
the information supplied;
nor shall GDUK be liable for any change or loss caused as a
result of reliance upon
such information.
Case Study 1: Success with Agile Project Management in
General Dynamics
Read the case study on General Dynamics attached.
The Combat Identification Server (CIdS) Technology
Demonstrator Project (TDP) has been delivered on time, with
quality and budget parameters using the Dynamic Systems
Development Method (DSDM). CIdS is a complex system and
software project. The objective is to help clear “the fog of war”
by providing a picture in the cockpit of an aircraft of the
position of nearby friendly forces on the ground. The selection
of DSDM for the CIdS TDP was motivated by the Tactical
Datalinks Delivery Team’s (TDL DT) objective to demonstrate
that complex military technologies could be delivered without
delay or cost overrun. The use of DSDM was a bold move, but

the CIdS project delivered successful outcomes for all involved.
In the current economic environment, delivering acceptable
solutions on time and at a fixed cost is surely a priority for the
Ministry of Defense (MoD). The success of the CIdS project has
provided a good example for the project management in the
defense sector.
Write a five to six (5-6) page paper in which you:
1. Speculate on the prominent reasons General Dynamics
selected the agile framework they did to use in this project.
2. Identify the major business problems the project team tried to
solve. Analyze the manner in which the project team applied the
agile project management techniques to ensure they delivered
the project on time, on budget with good quality.
3. Give your opinion if you agree with the approach(es)
identified in Question 2. Justify your response.
4. Analyze the manner in which the project teams and coaches
master the agile methodology to solve business problems.
Determine the approach that you believe is the most effective.
Provide a rationale for your response.
5. Determine whether or not the agile approach produced more
business benefits than a traditional project management
approach. Justify your response.
6. Provide your opinion on the agile coach’s role in this case
and determine if the coach is critical to the success of the
project. Support your answer.
Your assignment must follow these formatting requirements:
. Be typed, double spaced, using Times New Roman font (size
12), with one-inch margins on all sides; citations and references
must follow APA or school-specific format. Check with your
professor for any additional instructions.
. Include a cover page containing the title of the assignment, the
student’s name, the professor’s name, the course title, and the
date. The cover page and the reference page are not included in
the required assignment page length.

GB513: Business Analytics
1 of 5
Unit 3: Assignment
In this Assignment, you will be assessed based on the following
outcome:
GB513-2: Apply hypothesis testing and probability analysis to
solve business problems.
This Assignment has two parts. Part 1 has questions about
probability calculations. Part 2 has
questions about hypothesis testing. You will use Excel only in
Question 6. All other questions should
be calculated manually. Follow all instructions carefully.
Make sure to use the Unit 3 Assignment template located in the
Course Documents module to
submit your answers. Type in your calculations. Pictures of
hand written work are not acceptable.
Part 1
Question 1
In a class where the exam averages are normally distributed, the
mean score is 75 and the standard

deviation is 10. If you want to find out the probability that a
randomly picked student has scored 105
or above, what is the z-value that you should look up on the
normal distribution table?
Question 2
According to a report by Scarborough Research, the average
monthly household cellular phone bill is
$73. Suppose local monthly household cell phone bills are
normally distributed with a standard
deviation of $11.
a. W hat is the probability that a randomly selected monthly cell
phone bill is less than $95?
b. W hat is the probability that a randomly selected monthly cell
phone bill is between $62 and
$84?
Question 3
A Travel W eekly International Air Transport Association
survey asked business travelers about the
purpose for their most recent business trip. 19% responded that
it was for an internal company visit.
Suppose 950 business travelers are randomly selected.

a. W hat is the probability that more than 20% of the business
travelers say that the reason for
their most recent business trip was an internal company visit?
b. W hat is the probability that between 18% and 20% of the
business travelers say that the
reason for their most recent business trip was an internal
company visit?
2 of 5
Part 2
Question 4
Suppose a study reports that the average price for a gallon of
self-serve regular unleaded gasoline is
$3.16. You believe that the figure is higher in your area of the
country. You decide to test this claim
for your area of the United States by randomly calling gasoline
stations. Your random survey of 25

stations produces the following prices (all in dollars). Assume
gasoline prices for a region are
normally distributed.
Did the data you obtained provide enough evidence to reject the
claim? Use a 1% level of
significance.
Make sure you clearly state both the null and the alternative
hypotheses in full sentences. Following
your calculations, clearly state the conclusion in the same
manner (do not simply say “accept/rej ect
null”) and explain how you arrived at this conclusion (based on
which metrics).
3.27
3.3
3.16
3.15
3.11
3.05
3.54
3.25
3.05

3.11
3.13
3.15
3.27
3.14
3.14
3.2
3.3
3.09
3.05
3.07
3.37
3.34
3.35
3.35
3.1

3 of 5
Question 5
Where do CFOs get their money news? According to Robert
Half International, 47% get their money
news from newspapers, 15% get it from
communication/colleagues, 12% get it from television, 11%
from the Internet, 9% from magazines, 5% from radio, and 1%
do not know. Suppose a researcher
wants to test these results. She randomly samples 76 CFOs and
finds that 40 of them get their
money news from newspapers. Does the test show enough
evidence to reject the findings of Robert
Half International? Use a = .05.
hypotheses in full sentences. Following
your calculations, clearly state the conclusion in the same
manner (do not simply say “accept/reject
which metrics).

Question 6
To answer this question, use the Data Analysis Toolpack in
Excel and select “t -Test: Two-Sample
Assuming Equal Variances” from the list of available tools.
Conduct a hypothesis test using this tool.
Explain your answer (how you decided if men spend more or
not) and include the output table.
Some studies have shown that in the United States, men spend
more than women buying gifts and
cards on Valentine’s Day. Suppose a researcher wants to test
this hypothesis by randomly sampling
men and women with comparable demographic characteristics
from various large cities across the
United States to be in a study. Each study participant is asked to
keep a log beginning 1 month
before Valentine’s Day and record all purchases made for
Valentine’s Day during that 1-month
period. The resulting data are shown below. Use these data and
a 1% level of significance to test to
determine if, on average, men actually do spend significantly
more than women on Valentine’s Day.
Assume that such spending is normally distributed in the
population and that the population variances

are equal.
hypotheses in full sentences. Include the
output table; then, clearly state the conclusion in the same
manner (do not simply say “accept/reject
which metrics).
Men Women
107.48 125.98
143.61 59.32
90.19 96.35
125.53 80.62
70.79 77.6
83 84.34
129.63 75.21
154.22 68.48
4 of 5

93.8 65.84
111.25 126.11
78.6 82.54
89.35 123.5
Directions for submitting your Assignment
Make sure to use the Unit 3 Assignment template from Course
Resources when you turn in your
answers. Submit your Assignment to the Dropbox.
Unit 3 Assignment
Criteria
Points
Possible
Points
Earned
Question 1
The z-score for P(x> 95).
5

Question 2a
Probability that a randomly selected monthly cell phone bill is
less than
$95.
10
Question 2b
Probability that a randomly selected monthly cell phone bill is
between
$62 and $84.
10
Question 3a
Probability that more than 20% of the business travelers say
that the
reason for their most recent business trip was an internal
company visit.
10
Question 3b
Probability that between 18% and 20% of the business travelers

say
that the reason for their most recent business trip was an
internal
company visit.
10
Question 4
Correct null and alternative hypotheses in full sentences.
7
5 of 5
Question 4
Correct work, explanation, and conclusion in full sentences.
8
Question 5
7

Question 5
Correct work, explanation, and conclusion in full sentences.
8
Question 6
7
Question 6
Correct Excel table, explanation, and conclusion in full
sentences.
8
Properly completed Assignment template. 10
Total 100
Unit 3 Dropbox Assignment Answers by (Insert your name here)
In the summary tables below, insert only the answers. You will
show work after the summary section.
Question 1 answer
1
Z=

Question 2 answers
1a
P=
1b
P=
Question 3 answers
2a
P=
2b
P=
Question 4 answer
Make sure you use full sentences for the items below. Do not
simply say something like “x1<x2” “or “reject null” without a
description and explanation of how you arrived at your
conclusion.
Null hypothesis:
Alternative hypothesis:
Calculated t value:
Conclusion (justify using the metrics):
Question 5 answer
conclusion.
Null hypothesis:
Calculated z value:
Question 6 answer

conclusion.
Null hypothesis:
Calculated p or t value:
Work
Show all your work for the questions below.
Question 1
Show your work here.
Question 2
Show your work here.Question 3
Show your work here.
Question 4
Show your work here
Question 5
Show your work here
Question 6
Copy/paste the output table from the data analysis tool here and
explain how you arrived at your conclusion.

UNIT 3 .docx

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