Question 1

Given the frequency distribution for the number of pets per household:

Number of Pets: 1, 2, 3, 4, 5
Frequency: 150, 90, 110, 30, 20

What is the relative frequency of households with 3 pets? (Round to three decimal places)

$$	ext{Relative Frequency} = \frac{	ext{Frequency of 3 pets}}{	ext{Total Frequency}}$$

Accepted Answer

$$0.275$$

Question 2

Which of the following is the best graphical display to compare the marital status of U.S. residents in 1990 and 2006, as shown in the images above?

Accepted Answer

Side-by-side bar graph

Question 3

A histogram is shown for the Old Faithful geyser eruption times. If the class width is reduced from 10 seconds to 5 seconds, what is the most likely effect on the histogram?

Accepted Answer

The number of bars will increase and each bar will be shorter.

Question 4

Which of the following is a key difference between a bar graph and a histogram?

Accepted Answer

Bar graphs have gaps between bars, histograms have touching bars.

Question 5

A Pareto chart is most useful when you want to:

Accepted Answer

Display categories in decreasing order of frequency.

Question 6

Which of the following is a potential source of misleading information in a graph?

Accepted Answer

Starting the vertical axis at a value other than zero.

Question 7

Suppose you have the following data for the number of potholes on 1-mile stretches of highway: 1, 2, 3, 4, 5, 6, 7. The histogram is right-skewed. What does this indicate about the distribution?

Accepted Answer

Most stretches have a low number of potholes.

Question 8

Which of the following is NOT a reason to use a relative frequency distribution instead of a frequency distribution?

Accepted Answer

To display the actual counts in each category.

Question 9

A pie chart is most appropriate when you want to:

Accepted Answer

Compare the parts to the whole for a qualitative variable.

Question 10

Given the following frequency distribution for the number of pets per household:

Number of Pets: 1, 2, 3, 4, 5
Frequency: 150, 90, 110, 30, 20

What is the cumulative frequency for households with up to 3 pets?

$$	ext{Cumulative Frequency} = 150 + 90 + 110$$

Accepted Answer

$$350$$

Question 11

Which of the following best describes a bell-shaped (symmetric) distribution?

Accepted Answer

The highest frequency occurs in the middle and tails off evenly to both sides.

Question 12

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

Accepted Answer

Small to moderate discrete data sets

Question 13

Which of the following is a disadvantage of a stem-and-leaf plot compared to a histogram?

Accepted Answer

It becomes less useful with large data sets.

Question 14

If a bar graph is used to compare the number of M&Ms of different colors, what must be true about the bars?

Accepted Answer

They must have uniform width and be uniformly spaced.

Question 15

Which of the following is the correct formula for calculating the class width when organizing continuous data into classes?

$$	ext{Class Width} \approx \frac{	ext{Largest Data Value} - 	ext{Smallest Data Value}}{	ext{Number of Classes}}$$

Accepted Answer

$$	ext{Class Width} \approx \frac{	ext{Largest Data Value} - 	ext{Smallest Data Value}}{	ext{Number of Classes}}$$

Question 16

Which of the following is a reason to use a frequency polygon instead of a histogram?

Accepted Answer

To compare two or more data sets easily.

Question 17

A time-series plot is most appropriate for which of the following scenarios?

Accepted Answer

Displaying how a variable changes over time

Question 18

Which of the following is a graphical misrepresentation of data?

Accepted Answer

Using a bar graph with inconsistent bar widths

Question 19

If you want to compare the percentage of red M&Ms in two different bags, which type of frequency should you use?

Accepted Answer

Relative frequency

Question 20

Which of the following best describes a distribution that is skewed left?

Accepted Answer

The tail on the left is longer.

Describing Data with Tables and Graphs: Organizing and Displaying Qualitative and Quantitative Data

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