Question 1

Which of the following best describes a discrete variable?

Accepted Answer

A variable that has gaps between successive, possible values.

Question 2

A researcher records the number of books each student reads in a year. What type of variable is this?

Accepted Answer

Discrete variable

Question 3

Which of the following is an example of a continuous variable?

Accepted Answer

The amount of rainfall in millimeters during a storm

Question 4

In a dotplot, what does the height of the stack of dots above a value represent?

Accepted Answer

The frequency of that value

Question 5

A test score of 70 is at the 23rd percentile in a class of 35 students. How many students scored less than or equal to 70?

Accepted Answer

$$8$$

Question 6

If 13 out of 35 students scored at least 90 points on a test, what is the proportion of students who earned an A?

Accepted Answer

$$\frac{13}{35}$$

Question 7

Which of the following best defines an outlier?

Accepted Answer

An observation that is quite a bit smaller or larger than the other observations

Question 8

How is the stem and leaf determined for the value 375 in a stemplot?

Accepted Answer

Stem: 37, Leaf: 5

Question 9

A time-series plot is most appropriate for which type of data?

Accepted Answer

Data collected over a sequence of time intervals

Question 10

If the 15th percentile of a set of 40 test scores is needed, which calculation gives the position of the cutoff score?

Accepted Answer

$$0.15 	imes 40$$

Question 11

Which of the following statements about frequency distribution is correct?

Accepted Answer

It lists each observation together with its frequency.

Question 12

A dotplot of exam scores shows one value much lower than the rest. What is the most likely statistical term for this value?

Accepted Answer

Outlier

Question 13

Which of the following is NOT a correct step in constructing a stemplot?

Accepted Answer

Use the rightmost digit as the stem and the other digits as the leaf.

Question 14

A time-series plot is constructed for the annual revenue of a company from 2010 to 2020. What does the horizontal axis represent?

Accepted Answer

Time (years)

Question 15

If a student’s score is at the 50th percentile, what does this mean?

Accepted Answer

The student scored greater than or equal to approximately 50% of the class.

Question 16

Which of the following is a correct interpretation of the phrase 'at least 90 points' in the context of test scores?

Accepted Answer

Scores greater than or equal to 90 points

Question 17

A dotplot shows 7 dots to the left of 69 points. What does this indicate?

Accepted Answer

7 students scored less than or equal to 69 points

Question 18

Which of the following best describes the leaf in a stemplot for the value 92?

Accepted Answer

The digit 2

Question 19

Why might a test score of 38 be considered an outlier in a class where most scores are above 60?

Accepted Answer

Because it is much lower than the other scores

Question 20

Which of the following is the correct formula to find the number of observations at the kth percentile in a data set of size n?

Accepted Answer

$$\frac{k}{100} 	imes n$$

Chapter 3: Constructing Graphical and Tabular Displays of Data

Study Guide - Practice Questions