Question 1

Which of the following best describes the data that is collected in a statistical study for only a portion or subset of all elements of interest?

Accepted Answer

When data is collected for only a portion or subset of all elements of interest, it is called a sample. A census is the collection of data from all elements of interest, a parameter is a measure of a characteristic of a population, and a population is the entire group of elements of interest.

Question 2

Descriptive statistics deals with methods of:

Accepted Answer

Descriptive statistics involves organising, summarising, and presenting data in a way that is meaningful and informative. Therefore, all of the choices are correct.

Question 3

A summary measure that is computed from a population is called a population parameter.

Accepted Answer

A population parameter is a summary measure that is computed from a population, such as the population mean or population variance.

Question 4

Consider the population of all pencil manufacturers in the world. Describe any four examples of possible samples that could be taken from this population.

Accepted Answer

The answer of Consider the population of all pencil manufacturers...

Question 5

A local cable TV system using a sample of 500 subscribers finds that 40% of these subscribers watch a premium channel at least once per day. This is an example of statistical inference as opposed to
descriptive statistics.

Accepted Answer

This is an example of descriptive statistics because it describes data collected from a sample (the 40% of subscribers watching a premium channel) without making inferences about a larger population.

Question 6

A summary measure that is computed from a sample to describe a characteristic of the population is called:

Accepted Answer

A summary measure computed from a sample describes a characteristic of the sample and is called a statistic, while a summary measure computed from the entire population describes a characteristic of the population and is called a parameter. Therefore, the correct choice is B) a statistic.

Question 7

A summary measure that is computed from a population is called:

Accepted Answer

A parameter is a summary measure that is computed from a population, while a statistic is a summary measure that is computed from a sample. So, choice A is the best answer. Choice C is incorrect because a sample is not a summary measure, but rather a portion of the population from which a summary measure can be calculated. Choice D is incorrect because it includes both A and B, which are mutually exclusive.

Question 8

The significance level is the relative frequency of a wrong conclusion.

Accepted Answer

The significance level, often denoted by alpha (α), is the probability of rejecting the null hypothesis when it is actually true, representing the relative frequency of making a Type I error.

Question 9

Which of the following is the goal of descriptive statistics?

Accepted Answer

Descriptive statistics aim to summarise and display aspects of the collected data.

Question 10

A politician who is running for the office of premier in a state with 1 million registered voters commissions a survey. In the survey, 52% of the 3000 registered voters interviewed say they plan to vote for her. The sample is the:

Accepted Answer

The sample is the group of 3000 registered voters who were interviewed, as this is the group that was surveyed and provided the data for the survey results. The other choices are either the entire population of registered voters in the state (A), a specific subset of the surveyed voters (B), or a calculation based on the survey results (D), but none of them represent the sample itself.

Question 11

You ask five of your classmates about their height. On the basis of this information, you state that the average height of the students in the sample is 170 cm. Which of the following is this an example of?