Choose any two classmates and review their main posts. Review the student’s response to numbers 1 and 2 above. Compare these answers to your answers. Create a paragraph that offers this comparison and better explains why samples can estimate population parameters, but will never be 100% accurate. Review the student’s responses to numbers 3 and 4. Evaluate their work and answer. What variable did they choose? What were their sample mean, sample standard deviation, and sample sizes? Is their margin of error E correct? If yes, what is their margin of error and what does it tell you? If not, correct it and show all the work and steps. Student 1 post Deanna It is often impossible to know the actual value of any population parameters because populations are so large that we can’t possibly survey the whole population. One example I have been thinking of is- how many vegetarians there are in the U.S. To do this, we would have to survey each person in the U.S – which is impossible. Even on a smaller scale, another example is how many New Yorkers smoke. We would have to survey each New Yorker to find this value, and even though it is on a smaller scale to do this is impossible. Therefore, samples are so important. The sample size effects the estimate because depending on how the sample is pulled- it may alter the estimate.  For the example of smokers in NY, by chance we could choose a sample who are all nonsmokers. This would be a false estimate because the sample does not represent the whole population. There will always be errors because the sample is just a small portion being taken from the population. The sample could easily be skewed to one way and not be accurate.  Since populations could be very large – the sample could easily be taken from a certain area where the data will be the same and not varied. This will make the results un realistic.  Therefore it is impossible to get 100% accuracy. If we wanted 100% accuracy we would need to survey the entire population not missing one part. Using grades- the average came to 80.65 Standard Deviation – 9.4 Margin of Error = 2(9.4) / sqrt(20) = 4.20 80.65+4.20=84.85 80.65-4.20=76.45 The 95% confidence interval ( 76.45,84.85) Student 2 post Jola 1. It is often impossible to know the actual value of a population parameter because there will be almost no instance where you are able to get the data for the entire population.  Two examples of this would be the mean height and weight of females ages 21-35.  You are able to estimate this based on a sample of the population but it would be almost impossible to gather the date for the entire population of females 21-35. 2.  When using samples to estimate your data, the greater the sample size the closer the results are to the true population.  With smaller sample sizes you risk an inaccurate estimate to the true population mean.  3.  When using a sample to estimate a population there will always be errors because there are always outlie ...

1. Choose any two classmates and review their main posts.
Review the student’s response to numbers 1 and 2 above.
Compare these answers to your answers. Create a paragraph that
offers this comparison and better explains why samples can
estimate population parameters, but will never be 100%
accurate.
Review the student’s responses to numbers 3 and 4. Evaluate
their work and answer. What variable did they choose? What
were their sample mean, sample standard deviation, and sample
sizes? Is their margin of error E correct? If yes, what is their
margin of error and what does it tell you? If not, correct it and
show all the work and steps.
Student 1 post Deanna
It is often impossible to know the actual value of any population
parameters because populations are so large that we can’t
possibly survey the whole population. One example I have been
thinking of is- how many vegetarians there are in the U.S. To do
this, we would have to survey each person in the U.S – which is
impossible. Even on a smaller scale, another example is how
many New Yorkers smoke. We would have to survey each New
Yorker to find this value, and even though it is on a smaller
scale to do this is impossible. Therefore, samples are so
important.

2. The sample size effects the estimate because depending on how
the sample is pulled- it may alter the estimate. For the example
of smokers in NY, by chance we could choose a sample who are
all nonsmokers. This would be a false estimate because the
sample does not represent the whole population.
There will always be errors because the sample is just a small
portion being taken from the population. The sample could
easily be skewed to one way and not be accurate. Since
populations could be very large – the sample could easily be
taken from a certain area where the data will be the same and
not varied. This will make the results un realistic. Therefore it
is impossible to get 100% accuracy. If we wanted 100%
accuracy we would need to survey the entire population not
missing one part.
Using grades- the average came to 80.65
Standard Deviation – 9.4
Margin of Error = 2(9.4) / sqrt(20) = 4.20
80.65+4.20=84.85
80.65-4.20=76.45
The 95% confidence interval ( 76.45,84.85)
Student 2 post Jola
1. It is often impossible to know the actual value of a

3. population parameter because there will be almost no instance
where you are able to get the data for the entire population.
Two examples of this would be the mean height and weight of
females ages 21-35. You are able to estimate this based on a
sample of the population but it would be almost impossible to
gather the date for the entire population of females 21-35.
2. When using samples to estimate your data, the greater the
sample size the closer the results are to the true population.
With smaller sample sizes you risk an inaccurate estimate to the
true population mean.
3. When using a sample to estimate a population there will
always be errors because there are always outliers in any
population. Having outliers can impact the sample mean both
positively and negatively so we take a margin of error to
determine the confidence interval that we have for the sample.
Again the greater the sample size the smaller our confidence
interval will be (since to calculate the confidence interval you
are dividing by the square root of the size of the sample).
4. Using the data set for random female
weights[135,160,128,145,172,136,119,154,139,129,142,141,140
,154,163,152,158,139,144,146]
I was able to calculate the mean using the excel formula to be
144.8 as well as the standard deviation using excel to be
12.9436. To calculate my margin of error I have:
E= 1.96*s / sqrt (n) = 1.96(12.9436) / sqrt (20) = 25.3695 /
4.4721 = 5.6728
Therefore the 95% confidence interval would be [139.1272,
150.4728]

4. Respond to the next student post in a paragraph
Unit 9 Discussion
Christine Martinez
Messages such as email or text is one of the biggest
ambiguities used to communicate. I can think of a situation
where I sent an email to one of my coworkers. The email was of
a job posting, I was trying to send it to her as an FYI. The job
posting would have been a promotion and a higher paying job
for her. I was thinking the job would have been nice for her to
try to apply. She thought since I sent her the job that I knew
something about her getting the job. She had already applied
and by me sending her the job she thought I was trying to tell
her she got it.
When she approached me ready to celebrate I had to
clarify. I had to tell her that I did not know she applied and I
was sending her the job because I believed that she would be a
good fit. It was a let down for her and I was very embarrassed.
The truth is, that email, and texts are lazy ways used
to communicate these days, they leave every word that is
written open for interpretation and confusion. The more
messages that go back and forth the more the confusing the
conversation can get and can escalate without that being the
intent. The moral here is when there are too many messages
going back and forth, a face to face may be a better option.
Soleam post

5. Working from home is the best thing happened to me, for
now. I do not have to drive to work; I do not have a work
schedule and no late meetings. However, sometimes the
communication with the supervisors can be a real challenge.
One of the requirements in my work is that the communication
between the teamwork should be by email because of the
difference in time zone. We start a new project every six
months. When we are starting a new project, the supervisor
sends the instructions along with the guidelines of the
designated project.
In occasions, I have to deal with the discrepancy between
the guidelines and the instructions, and in order to complete the
work satisfactorily, we must follow both, the guidelines and the
instructions. The communication by email can be a little slow,
since the difference in time zone, In times, I have to stop the
work for a day or so just waiting for an answer or approval. In
my opinion, to communicate more effectively, the supervisors
can set up a telephone call meeting with all the teamwork when
a new project starts, so everyone can talk about possible doubts,
or just talk about the expectations of the new projects so that
everyone can be on the same page at the same time.