Question 1

Read the below scenario and then answer the questions that follow.

The Ancestry Society of North Carolina is compiling records so they can learn

about the history of African Americans in North Carolina from 1820 to 1980. They

have compiled records of all 15,125 gravestones in cemeteries across all 15

counties. They want to choose a sample of 600 records to check their accuracy

by visiting the actual gravestones.

a) Using the hat method explain how they could gather a simple random sample

of 600 gravestones to visit.

b) Explain why it would be better to take a sample 40 gravestones from all 15

counties.

c) For what population could they make inference about after gathering and

examining the sample?

Question 2

Read the below scenario and then answer the questions that follow.

Part 1

Amazon claims that if you are a prime member, 85% of your packages will arrive

within two business days. You have decided that you want to know if this claim is

true. You take a simple random sample of 25 students at your school and 19 of

the students claim that their packages arrived within two business days of

ordering.

a. What is the population proportion? What is the sample proportion? Please use

correct symbols in your answer.

Population Proportion Symbol:

Population Proportion:

Sample Proportion Symbol:

Sample Proportion:

b. Create a bar graph below that would exaggerate the findings from part a. You

want the reader to think that Amazon is not holding up to its claim.

Please give your graph an eye catching title that would make someone mistrust

Amazon.

TITLE:

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Part 2

You decide that you want to make sure your estimate from part a is correct. You

go out and gather 10 simple random samples of 25 people in your school and

calculate the proportion of students within each sample whose Amazon

packages arrive within two business days of ordering.

The proportion of customers that receive their packages within two days of

ordering are given below.

0.70, 0.75, 0.6, 0.95, 0.90, 0.73, 0.87, 0.86, 0.92, 0.97

a. Explain why all of the sample proportions are not the same.

b. Find the average of all 10 proportions above.

c. Compare this to the sample proportion you found in a of part 1. Are they the

same or different?

Sample Proportion from Part 1: _________________

Sample Proportion from Part a: _________________

d. Find the margin of error for the 10 samples.

e. How can we decrease the margin of error?

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f. Based on Amazon’s claim of 85% and your sample proportions, do you

believe Amazon’s claim? Explain.

Question 3

Researchers in New Zealand conducted an experiment with college students at

Victoria University to determine the effects of in- class tablet use on student

learning. All participants were asked to attend to attend a class and take their

tablet.

● 25 students used the tablets solely to take notes.

● 25 students were assigned to do non classroom related activities such as

web browsing and checking social media during class.

● The final 25 students were asked to take notes on notebook paper.

● When the students entered the classroom they picked a piece of paper out

of the hat. 25 said paper, 25 stated notes on laptop, and 25 stated web

browsing on laptop.

● Students were to work in class based on what they picked out of the hat.

● At the end of the class, all students took a comprehension test to

determine how much they learned from class.

● The result was that students who were multitasking on the computer had

13% less comprehension than the students who were taking notes on the

laptop or by paper.

a. What was the treatment? (There are two)

Treatment 1: ________________________________

Treatment 2: ________________________________

b. What was the control group?

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c. What were researchers comparing in this experiment?

d. Can we establish cause and effect here? Why or why not?

e. For what population could we make inference?

f. Explain why this is an experiment and not an observational study