Question 1

Which of the following best describes a histogram?

Accepted Answer

A graph that uses bars to portray the frequencies or relative frequencies of possible outcomes for a quantitative variable.

Question 2

A distribution is said to be skewed to the right if:

Accepted Answer

The right tail is longer than the left tail.

Question 3

Which graphical summary is most appropriate for displaying the distribution of the number of hours students watch TV per week (a quantitative variable) for a large class?

Accepted Answer

Histogram

Question 4

What is the main advantage of a bar graph over a pie chart when summarizing categorical data?

Accepted Answer

It is usually easier to compare categories with a bar graph.

Question 5

Given the following frequency table for sodium in cereals, what is the relative frequency for the interval 120 to 159 mg if there are 20 cereals in total and 4 cereals fall in this interval?

Accepted Answer

$$0.20$$

Question 6

Which of the following is NOT a key feature to identify when interpreting a histogram?

Accepted Answer

The color of the bars

Question 7

A time plot is most useful for:

Accepted Answer

Displaying how a variable changes over time

Question 8

If a histogram of exam scores is symmetric, what does this imply about the distribution of scores?

Accepted Answer

The left and right sides of the histogram are mirror images of each other.

Question 9

Which of the following is an example of an outlier?

Accepted Answer

A value that falls far above or below the bulk of the observations.

Question 10

A stem-and-leaf plot is most useful for:

Accepted Answer

Displaying all individual values in a small quantitative data set.

Question 11

Which of the following best describes a Pareto chart?

Accepted Answer

A bar graph where categories are ordered by frequency from tallest to shortest bar.

Question 12

If a distribution of incomes is skewed to the right, what does this indicate?

Accepted Answer

Most people have lower incomes, but a few have very high incomes.

Question 13

Which graphical summary would be most appropriate for showing the proportion of deaths by cause in Canada in 2018?

Accepted Answer

Pie chart

Question 14

A dot plot is most useful for which type of data?

Accepted Answer

Small quantitative data sets

Question 15

Which of the following is a correct step in constructing a histogram?

Accepted Answer

Divide the range of the data into intervals of equal width.

Question 16

If a histogram of test scores is skewed to the left, what does this suggest about the test?

Accepted Answer

Most students scored high, but a few scored much lower.

Question 17

Which of the following is a categorical variable?

Accepted Answer

Type of car (sedan, SUV, truck)

Question 18

What is the main difference between a bar graph and a histogram?

Accepted Answer

A bar graph is used for categorical data, while a histogram is used for quantitative data.

Question 19

Which of the following best describes the center of a distribution?

Accepted Answer

A value that divides the data so that 50% of the observations are below and 50% are above.

Question 20

A time plot of internet usage from 1995 to 2001 shows a steady increase. What is the most appropriate conclusion?

Accepted Answer

There is an upward trend in internet usage over time.

Describing Data with Graphs: Categorical and Quantitative Variables

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