Question 1

A new stadium is being planned for the local professional football team. One of the proposed funding methods involves the allocation of tax monies to build the stadium. To determine the public opinion of this plan, the first 100 people entering the stadium for a game are surveyed. Explain why the results of this survey might not be valid.

Accepted Answer

The answer of A new stadium is being planned for...

Question 2

A marketing company conducted a survey of college students to obtain data for an advertising campaign. They selected 1421 students randomly from campus directories of 132 colleges and universities. The students in the directories at the 132 colleges and universities represent:

Accepted Answer

The students in the directories at the 132 colleges and universities represent the entire population of college students, as the directories cover all students at the chosen schools. Therefore, the 1421 students selected from these directories represent a sample of the population.

Question 3

Officials at a university conduct a survey to determine the percentage of students who favor the allocation of a percentage of tuition funds toward the construction of a new campus parking garage. One thousand people driving through the administration building parking lot are surveyed, and it is found that 75% of these people favor the garage. What is the population in this study? What is the sample?

Accepted Answer

The answer of Officials at a university conduct a survey...

Question 4

Officials at a university conduct a survey to determine the percentage of students who favor the allocation of a percentage of tuition funds toward the construction of a new campus parking garage. One thousand people driving through the administration building parking lot are surveyed, and it is found that 75% of these people favor the garage. Explain why this conclusion might not be valid.

Accepted Answer

The answer of Officials at a university conduct a survey...

Question 5

A marketing company conducted a survey of college students to obtain data for an advertising campaign. They selected 1421 students randomly from campus directories of 132 colleges and universities. The 1421 students represent:

Accepted Answer

The 1421 students selected represent the sample, as they are a subset of the larger population of college students at 132 colleges and universities.

Question 6

You take a simple random sample of 500 from a large population. If the population proportion is p = 0.2, describe the sampling distribution in terms of shape, center and variability.

Accepted Answer

The answer of You take a simple random sample of...

Question 7

You sample all 1000 people in the population of interest and find that $\hat { p }$ is 0.2. Why should you not use the margin of error formula to find a 95% confidence interval for p?

Accepted Answer

The answer of You sample all 1000 people in the...

Question 8

A poll asks 312 randomly selected students whether they prefer the new beaver mascot or the old moose mascot. It turns out that the sample proportion $\hat { p }$ for those preferring the moose is 0.54. What is the margin of error for a 95% confidence interval?

Accepted Answer

The answer of A poll asks 312 randomly selected students...

Question 9

To estimate the proportion of voters in a town likely to favor a tax increase for road repair, a random sample of people chosen from the voter registration list is surveyed and the proportion who favors the increase is found to be 43%. The actual proportion in the town is 40%. This difference is most likely an example of sampling:

Accepted Answer

This difference is an example of sampling variability, which refers to the natural fluctuations that occur from one sample to another. It is not indicative of a systematic error (bias) in the sampling method.

Question 10

Describe what is meant by the placebo effect in an experiment.

Accepted Answer

The answer of Describe what is meant by the placebo...

Question 11

A polling company conducted a survey of voters to obtain data for a political campaign. They selected 3500 voters randomly from the 168,000 names on the voter registration lists of the county and found that 1372 intended to vote for candidate Doe. The 168,000 names represent:

Accepted Answer

The 168,000 names on the voter registration lists represent the entire group (population) of registered voters in the county. The polling company selected a random sample of 3500 voters from this population to gather data for their survey. Therefore, the correct choice is A.

Question 12

Explain the difference between a parameter and a statistic.

Accepted Answer

The answer of Explain the difference between a parameter and...

Question 13

How does a randomized comparative experiment control the effects of confounding variables?

Accepted Answer

The answer of How does a randomized comparative experiment control...

Question 14

A survey of 127 patients in a particular hospital determined that 54% of them felt that they were receiving excellent care. Determine the 95% confidence interval for this survey.

Accepted Answer

The answer of A survey of 127 patients in a...

Question 15

What is nonresponse?

Accepted Answer

The answer of What is nonresponse?...

Question 16

Medical experiments are frequently double-blind. Explain what this means and why medical experiments are designed this way.

Accepted Answer

The answer of Medical experiments are frequently double-blind. Explain what...

Question 17

What does it mean to say that the results of an experiment are statistically significant?

Accepted Answer

The answer of What does it mean to say that...

Question 18

In order to determine the mean weight of bags of chips filled by its packing machines, a company inspects 50 bags per day and weighs them. In this example, the population is:

Accepted Answer

The population refers to the entire group that is the subject of the study. In this case, since the company is interested in the mean weight of bags of chips it fills, the population includes all bags of chips produced by the company, not just the 50 bags inspected daily or any other subset.

Question 19

A polling company conducted a survey of voters to obtain data for a political campaign. They selected 3500 voters randomly from the 168,000 names on the voter registration lists of the county and found that 1372 intended to vote for candidate Doe. The 3500 voters represent:

Accepted Answer

The 3500 voters represent the sample, as they were randomly selected from the larger population of 168,000 voters. The sample was used to obtain data on voting intentions, which can be extrapolated to make predictions about the larger population.

Question 20

A recent survey of 536 employees of U.S. corporations determined that 84% of them feel that the executives who run their companies are ethical. Determine the 95% confidence interval for this survey.

Accepted Answer

The answer of A recent survey of 536 employees of...

Quiz 7: Data for Decisions