Question 1

Which of the following best describes the difference between a population and a sample in statistics?

Accepted Answer

A population includes all experimental units of interest, while a sample is a subset of the population.

Question 2

A researcher wants to estimate the average income of all families in Toronto. She surveys 5,000 households and calculates the average income from her data. In this context, what is the statistic?

Accepted Answer

The average income calculated from the 5,000 households.

Question 3

Which of the following is an example of inferential statistics?

Accepted Answer

Using a sample of 1,000 voters to predict the outcome of a national election.

Question 4

Which of the following variables is qualitative (categorical)?

Accepted Answer

Marital status (single, married, divorced)

Question 5

A manufacturer claims that less than 5% of his toys are defective. In a sample of 500 toys, 8% are found to be defective. What is the parameter in this context?

Accepted Answer

The true proportion of defective toys in the entire production.

Question 6

Which of the following best describes a simple random sample?

Accepted Answer

A sample where each possible sample of the same size has an equal chance of being selected.

Question 7

A bar chart is most appropriate for displaying which type of data?

Accepted Answer

Qualitative (categorical) data

Question 8

Which of the following is a potential source of measurement error in a survey?

Accepted Answer

Ambiguous or leading questions

Question 9

Given the following data set: $$x_1 = 2$, x_2$ = 4$$, $$x_3 = 6$, x_4$ = 8. $$What is $$\sum_{i=1}^{4} x_i$$?

Accepted Answer

$$20$$

Question 10

Which of the following best describes a histogram?

Accepted Answer

A graph where bars represent frequencies of quantitative data and are adjacent to each other.

Question 11

A university administrator follows 250 students and records the time it takes each to find a parking spot. What type of data collection method is this?

Accepted Answer

Observational study

Question 12

Which of the following is an example of a discrete quantitative variable?

Accepted Answer

Number of computers in a household

Question 13

In a frequency table for qualitative data, what does the class relative frequency represent?

Accepted Answer

The number of observations in a class divided by the total number of observations.

Question 14

Which of the following is an example of selection bias?

Accepted Answer

Some groups in the population have no chance of being selected in the sample.

Question 15

A pie chart is most useful for displaying:

Accepted Answer

The distribution of a categorical variable as proportions of a whole.

Question 16

Which of the following best describes the mean of a sample?

Accepted Answer

It is denoted by $$\overline{x}$$ and represents the average of the sample data.

Question 17

A researcher wants to test if a new drug is effective. She gives the drug to 95 patients and a placebo to another 95 patients, then compares the results. What type of data collection method is this?

Accepted Answer

Designed experiment

Question 18

Which of the following is a measure of central tendency?

Accepted Answer

Median

Question 19

If a histogram has a longer right-hand tail, how is it described?

Accepted Answer

Positively skewed

Question 20

Which of the following is an example of nonresponse bias?

Accepted Answer

Some survey participants do not answer the questionnaire.

Introduction to Statistics: Foundations and Data Description

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