Question 3
In order to determine who will win footballs autographed by a football player, a computer program randomly selects ticket numbers of 10 people who were in the stadium that day. What is the type of sampling?
Group of answer choices

simple random sampling

stratified sampling

systematic sampling

cluster sampling

convenience/haphazard sampling

volunteer sample

Question 4
A population of taxpayers is divided into five income levels and a simple random sample is selected from each income level for an audit. What is the type of sampling?
Group of answer choices

simple random sampling

stratified sampling

systematic sampling

cluster sampling

convenience/haphazard sampling

volunteer sample

Question 5
A restaurant chain randomly selected 30 restaurants from all possible restaurants in the chain. All customers in each of the selected restaurants were asked to fill out a survey. What is the type of sampling?
Group of answer choices

simple random sampling

stratified sampling

systematic sampling

cluster sampling

convenience/haphazard sampling

volunteer sample

Question 6
A New York City newspaper reporter wants to know if New Yorkers would be willing to incur higher electricity bills in order to upgrade an antiquated grid that transmits electricity to New York City. The reporter stood at Times Square and collected opinions from 200 people who passed by that day. What is the type of sampling?
Group of answer choices

simple random sampling

stratified sampling

systematic sampling

cluster sampling

convenience/haphazard sampling

volunteer sample

Multiple Choice Questions

Question 7
A question on a youth survey was “How well do you get along with your parents?” The survey showed that 54% of the randomly selected teenagers said they get along “very well.” The reported margin of error was 5%. Construct the interval that we would expect to cover the true population value. (This interval is the confidence interval for the population percent who get along well.) Based on your calculated interval, is it reasonable to infer that the majority of teenagers get along “very well” with their parents?
Group of answer choices

No, it is not reasonable to infer that the majority get along well since the confidence interval contains values of 50% and below.

Yes, it is reasonable to infer that the majority get along well since most of the values in the interval are above 50%.

Yes, it is reasonable to infer that the majority get along well since the sample percent is 54% which is a majority.

Question 8
A STAT 100 class was divided by gender. A sample of randomly selected males and a sample of randomly selected females were asked “Do you believe in love at first sight?” The margin of error for the sample of males was 5% while the margin of error for the sample of females was 4%. Based on how the margin of error is calculated, what is the explanation for why the two margins of error are not the same?
Group of answer choices

Female sample size is smaller than the male sample size

Female sample size is larger than the male sample size

Not enough information is given to answer the question

Question 9
Which of the following surveys would have the largest margin of error?
Group of answer choices

a random sample of n = 1000 from a population of 10 million

a random sample of n = 500 from a population of 10 million

a random sample of n = 1100 from a population of 20 million

a random sample of n = 400 from a population of 20 million

Use the information below to answer the questions that follow:

Researchers asked a sample of 50 1st grade teachers and a sample of 50 12th grade teachers how much of their own money they spent on school supplies in the previous school year. They wanted to see if teachers at one grade level spend more than teachers at the other grade level.

Question 10
What type of study is found?
Group of answer choices

randomized experiment

observational study

both an observational study and s randomized experiment

Question 11
What is the response variable?
Group of answer choices

a teacher

the amount of money spent on school supplies the previous year

the grade the teacher teaches

the school supplies

Question 12
What is the explanatory variable?
Group of answer choices

teacher

the amount of money spent on school supplies the previous year

the grade level the teacher teaches

the school supplies

Question 13
What variables could be confounding variables in this instance?
Group of answer choices

number of years the teacher has been teaching

amount of money spent on school supplies

grade the teacher teaches

all of the above choices are possible confounding variables

confounding variables are not possible in this study

Question 14
Is this a retrospective or prospective study?
Group of answer choices

This is a prospective study.

This is a retrospective study.

Use the information below to answer the questions that follow:

A research team compared two methods of measuring tread wear on tires. Eleven tires were each measured for tread wear by two different methods: one method was based on weight while the other method was based on groove wear. For convenience, each tire was measured first by weight method and then second by the groove wear.

Question 15
What type of study is this?
Group of answer choices

observational study

randomized experiment

Question 16
The two samples are ___________.
Group of answer choices

two independent samples

two dependent samples (i.e. matched pairs)

Question 17
What is the experimental or observational unit?
Group of answer choices

method of measurement of tread wear (weight or groove wear)

amount of tread wear

a tire

Multiple Select Questions

Question 184 pts
A study wants to determine if taking fish oils can reduce depressive symptoms. A group of 50 volunteers who suffered from mild depression were randomly divided into two groups. Each person was given a three-months supply of capsules. One group was given capsules that contained fish oils while the other group was given capsules that look and tasted like fish oils, but actually only contained sugar and inert ingredients. Neither the participants nor the investigator knew what type of capsule they were taking. At the end of the month, a psychologist evaluated them to determine if their depressive symptoms had changed. Therefore, we are comparing the change in depressive symptoms for individuals in two groups. Which of the following applies to this study? (choose all that apply)
Group of answer choices

observational study

randomized experiment

placebo

single-blind

double-blind

matched pairs (dependent samples)

block design

independent samples

Question 19
Does the use of cell phones lead to a higher incidence of brain cancer? People with brain cancer were matched with people who did not have brain cancer on age, gender, and living environment. Each participant in the study was asked to answer questions about previous life experiences and exposures. Which of the following applies to this observational study? (choose all that apply)
Group of answer choices

prospective

retrospective

case-control study

Essay Questions

Refer to the article How Polls Are Conducted when answering the remaining questions.  See the link in the “To Do” list for this lesson

Question 20
About what aspect(s) of the Gallup Poll are Americans most skeptical?

Question 21
What, if anything, have you learned either from this lesson or this article that helps you not share the same skepticism described in the Gallup Poll article?

Question 22
What is probability sampling as defined by the Gallup Poll?

Question 23
Often households have more than one adult who is a part of Gallup Polls sampling frame. How does Gallup randomly sample from these households?