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? A. To summarise data.
B To display aspects of the collected data.
C To summarise data and display aspects of the collected data.
D To estimate characteristics of the popul ation.

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?

Accepted Answer

Descriptive statistics involve summarizing and describing a sample or population, such as computing measures of central tendency (like the mean or average) and measures of variability (like the standard deviation). In this scenario, the statement about the average height of the sample describes the sample itself and is an example of descriptive statistics. Inferential statistics involve making predictions or generalizations about a population based on a sample, but there is no mention of a larger population in this scenario. A census would involve collecting data from an entire population, not just a sample. A population parameter is a numerical value that describes a characteristic of a population, but again, there is no mention of a larger population in this scenario.

Question 12

Which of the following statements is true?

Accepted Answer

Descriptive statistics uses both graphical and numerical techniques to summarize and describe data, while statistical inference is used to make conclusions about a larger population based on a sample of data. Therefore, option D is the only statement that accurately describes the use of statistical inference in data analysis.

Question 13

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

Accepted Answer

This definition accurately describes a statistic.

Question 14

Statistical inference is the process of making an estimate, prediction or decision about a population, based on sample data.

Accepted Answer

Statistical inference involves using sample data to make inferences about a population parameter. This can include making estimates, predictions or decisions using techniques such as confidence intervals, hypothesis testing or regression analysis. Therefore, the statement is true.

Quiz 1: What Is Statistics