This document provides a review of percents for a math class. It includes definitions of percents, examples of equivalent ratios expressed as percents, and multiple choice and word problems involving calculating and comparing percents. The problems cover topics like determining percentages of totals, comparing ratios, sales tax calculations, and determining if driving farther for a purchase is worth it based on potential savings and gas costs.
Lärdomar från tio stadsregioner.
En presentation för näringslivsutvecklare i Göteborg och Västra Götalands-regionen.
Presentation den 19 juni 2012 av Örjan Sölvell och Göran Lindqvist, Lindholmen Sciencepark.
Lärdomar från tio stadsregioner.
En presentation för näringslivsutvecklare i Göteborg och Västra Götalands-regionen.
Presentation den 19 juni 2012 av Örjan Sölvell och Göran Lindqvist, Lindholmen Sciencepark.
Answer all 20 questions. Make sure your answers are as complet.docxfestockton
Answer all 20 questions. Make sure your answers are as complete as possible, particularly when it asks for you to show
your work. Answers that come straight from calculators, programs or software packages without any explanation will
not be accepted. If you need to use technology (for example, Excel, online or hand-held calculators, statistical packages)
to aid in your calculation, you must cite the sources and explain how you get the results. For example, state the Excel
function along with the required parameters when using Excel; describe the detailed steps when using a hand-held
calculator; or provide the URL and detailed steps when using an online calculator, and so on.
Record your answers and work on the separate answer sheet provided.
This exam has 20 problems; 5% for each problems.
STAT 200: Introduction to Statistics
Final Examination, Fall 2019 OL1
1. You wish to estimate the mean cholesterol levels of patients two days after they had a heart attack. To estimate the
mean, you collect data from 28 heart patients. Justify for full credit.
(a) Which of the followings is the sample?
(i) Mean cholesterol levels of 28 patients recovering from a heart attack suffered two days ago
(ii) Cholesterol level of the person recovering from heart attack suffered two days ago
(iii) Set of all patients recovering from a heart attack suffered two days ago
(iv) Set of 28 patients recovering from a heart attack suffered two days ago
(b) Which of the followings is the variable?
(i) Mean cholesterol levels of 28 patients recovering from a heart attack suffered two days ago
(ii) Cholesterol level of the person recovering from heart attack suffered two days ago
(iii) Set of all patients recovering from a heart attack suffered two days ago
(iv) Set of 28 patients recovering from a heart attack suffered two days ago
2. Choose the best answer. Justify for full credit.
(a) The Knot.com surveyed nearly 13,000 couples, who married in 2017, and asked how much they spent on their
wedding. The average amount of money spent on was $33,391. The value $33,391 is a:
(i) parameter
(ii) statistic
(iii) cannot be determined from information provided.
(b) A marketing agent asked people to rank the quality of a new soap on a scale from 1 (poor) to 5 (excellent). The level
of this measurement is
(i) nominal
(ii) ordinal
(iii) interval
(iv) ratio
3. True or False. Justify for full credit.
(a) If the variance from a data set is zero, then all the observations in this data set must be identical.
(b) The median of a normal distribution curve is always zero.
4. A STAT 200 student is interested in the number of credit cards owned by college students. She surveyed all of her
classmates to collect sample data.
(a) What type of sampling method is being used?
(b) Please explain your answer.
5. A study was conducted to determine whether the mean braking distance of four-cylinder cars is greater than th ...
InstructionDue Date 6 pm on October 28 (Wed)Part IProbability a.docxdirkrplav
InstructionDue Date: 6 pm on October 28 (Wed)
Part IProbability and Sampling Distributions1.Thinking about probability statements. Probability is measure of how likely an event is to occur. Match one of probabilities that follow with each statement of likelihood given (The probability is usually a more exact measure of likelihood than is the verbal statement.)Answer0 0.01 0.3 0.6 0.99 1(a) This event is impossible. It can never occur.(b) This event is certain. It will occur on every trial.(c) This event is very unlikely, but it will occur once in a while in a long sequence of trials.(d) This event will occur more often that not.2. Spill or Spell? Spell-checking software catches "nonword errors" that result in a string of letters that is not a word, as when "the" is typed as "the." When undergraduates are asked to write a 250-word essay (without spell-checking), the number X of nonword errors has the following distribution:Value of X01234Probability0.10.20.30.30.1(a) Check that this distribution satisfies the two requirements for a legitimate assignment of probabilities to individual outcomes.(b) Write the event "at least one nonword error" in term of X (for example, P(X >3)). What is the probability of this event?(c) Describe the event X ≤ 2 in words. What is its probability? 3. Discrete or continuous? For each exercise listed below, decide whether the random variable described is discrete or continuous and explains the sample space.(a) Choose a student in your class at random. Ask how much time that student spent studying during the past 24 hours.(b) In a test of a new package design, you drop a carton of a dozen eggs from a height of 1 foot and count the number of broken eggs.(c) A nutrition researcher feeds a new diet to a young male white rat. The response variable is the weight (in grams) that the rat gains in 8 weeks.4. Tossing Coins(a) The distribution of the count X of heads in a single coin toss will be as follows. Find the mean number of heads and the variance for a single coin toss.Number of Heads (Xi)01mean:Probability (Pi)0.50.5variance:(b) The distribution of the count X of heads in four tosses of a balanced coin was as follows but some missing probabilities. Fill in the blanks and then find the mean number of heads and the variance for the distribution with assumption that the tosses are independent of each other.Number of Heads (Xi)01234mean:Probability (Pi)0.06250.0625variance:(c) Show that the two results of the means (i.e. single toss and four tosses) are related by the addition rule for means. (d) Show that the two results of the variances (i.e. single toss and four tosses) are related by the addition rule for variances (note: It was assumed that the tosses are independent of each other). 5. Generating a sampling distribution. Let's illustrate the idea of a sampling distribution in the case of a very small sample from a very small .
1. Name Date
Math Period _____
Unit 8 – Percents – Review the “Common – Core” Way
I. Information
a) A percent is a ratio that compares a number to 100. The symbol % is used to show a percent.
17 % is equivalent to:
17 to 100
17 : 100
II. Review Questions
1)
2. 2) At King Kullen, .33 of the shelves hold meat products, 27 % of the shelves hold dairy items and of the shelf space is
used for snack items. Place the items in order from least to greatest in terms of the amount of shelf space that they take
up.
3) A review of the population of sixth graders at Nesaquake Middle School is shown in the table below.
6 th Grade :
Class: Mr. A Mrs. B Mrs. F Mr. P
Number of boys 13 12 12 11
Number of girls 11 14 12 14
a) Which class has a 1:1 ratio of boys to girls?
b) Which class is made up of 44 % boys?
c) What is the ratio of girls to boys for all four classes combined?
4) Replace the x, y and z in the tables of equivalent ratios with the correct number. Do not simplify the answers.
a) x = _________ y = ________ z= _________
1:7
10:x
3. b) x = _________ y = ________ z= _________
2 : 11
6 :x
5) Bill works in a hardware store. Sixteen hours represents 40 % of Bill’s work week. How many hours does Bill work in a
week?
6) Caroline ordered 20 pizzas for a party. 7 of those pizzas were just cheese. What percent of those pizzas were just
cheese?
7) 15 children in Mr. Smith’sclass are boys. If there are a total of 25 students in the class, what percent of the class are
GIRLS?
4. 8) Bruce saved $35 to buy a new video game. The game’s original price was $ 42, but it was on sale for 30 % off. The
sales tax rate was 5%. Did Bruce have enough money to buy the game? Explain.
9) Use the following two tables to help you in answering the questions below.
Sales Tax Table
New York 8%
New Jersey 7%
Connecticut 6%
Wal – Mart Prices
Television $699.95
I – Pad $ 399.95
Computer $ 1299.95
DVD Player $ 199.95
Different states and counties have different tax rates. A family living on the border of Connecticut and New York has
decided to travel to Connecticut to purchase a TV and a DVD player due to the fact that the tax rate is lower in
Connecticut. Round to the nearest whole dollar amount.
a) Calculate the total cost (with sales tax) of the two items in New York.
5. b) Calculate the total cost of the two items in Connecticut?
c) How much is being saved by purchasing the two items in Connecticut?
d) It is approximately 40 miles longer of a drive for the family to travel to Connecticut to purchase the items. If
the gas is $ 3.85 per gallon and the car gets 20 miles to the gallon, is it worth it for the family to drive to Connecticut?
Defend your answer using math.