Q: A pie chart is constructed to represent the marital status of U.S. residents in 2006. If 58% were married, what is the central angle for the 'Married' sector? Use $$\text{Angle} = \text{Percent} \times 360^\circ.$$

$$0.58 \times 360^\circ = 208.8^\circ$$

Question 1

Which of the following best describes a frequency distribution for qualitative data?

Accepted Answer

A table that lists each category of data and the number of occurrences for each category.

Question 2

Given the following frequency table for M&M colors: Brown (12), Yellow (10), Red (9), Orange (6), Blue (3), Green (5), what is the relative frequency of Red M&Ms? Use the formula $$	ext{Relative Frequency} = \frac{	ext{Frequency}}{	ext{Total}}.$$

Accepted Answer

$$\frac{9}{45} = 0.2$$

Question 3

Which type of graph is most appropriate for displaying the relative frequencies of different categories of a qualitative variable?

Accepted Answer

Bar graph

Question 4

A pie chart is constructed to represent the marital status of U.S. residents in 2006. If 58% were married, what is the central angle for the 'Married' sector? Use $$	ext{Angle} = 	ext{Percent} 	imes 360^\circ.$$

Accepted Answer

$$0.58 	imes 360^\circ = 208.8^\circ$$

Question 5

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

Accepted Answer

Histograms are used for quantitative data and bars touch; bar graphs are used for qualitative data and bars do not touch.

Question 6

A frequency distribution for the time between eruptions at Old Faithful uses class intervals of 10 seconds, starting at 670 seconds. What is the class width, and how is it calculated?

Accepted Answer

Class width is 10, calculated as $$680 - 670 = 10$$

Question 7

Which of the following best describes a Pareto chart?

Accepted Answer

A bar graph where the bars are drawn in decreasing order of frequency or relative frequency.

Question 8

Suppose you are comparing the educational attainment of two different years using a bar graph. Why should you use relative frequencies instead of frequencies?

Accepted Answer

Because the sample sizes may differ, making frequencies misleading.

Question 9

Which of the following is an advantage of a stem-and-leaf plot over a histogram?

Accepted Answer

The raw data can be retrieved from a stem-and-leaf plot.

Question 10

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

Accepted Answer

Small sets of discrete quantitative data

Question 11

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

Accepted Answer

The highest frequency occurs in the middle and frequencies tail off to the left and right.

Question 12

If a histogram of household income is skewed right, what does this indicate about the distribution?

Accepted Answer

There are a few households with much higher incomes than the rest.

Question 13

Which of the following is a guideline for constructing good graphics?

Accepted Answer

Title and label the axes clearly, including units of measurement.

Question 14

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

Accepted Answer

Tracking the closing price of a stock over several years.

Question 15

Which of the following could make a graph misleading or deceptive?

Accepted Answer

Truncating the vertical axis to exaggerate differences.

Question 16

Given a data set with a minimum value of 25 and a maximum value of 74, and you want to create 10 classes for a histogram, what is the class width? Use $$	ext{Class Width} = \frac{	ext{Max} - 	ext{Min}}{	ext{Number of Classes}}$$ and round up.

Accepted Answer

$$\frac{74 - 25}{10} = 4.9$$, so class width is 5

Question 17

Which of the following is NOT a recommended practice when constructing a pie chart?

Accepted Answer

Using three-dimensional effects to make the chart more visually appealing.

Question 18

A misleading pie chart is created by exaggerating the size of one sector. What is the likely effect on the interpretation of the data?

Accepted Answer

Viewers may overestimate the importance of that category.

Question 19

Which of the following best describes a uniform distribution?

Accepted Answer

The frequency of each value is evenly spread out across the values.

Summarizing Data in Tables and Graphs: Introductory Statistics Study Guide

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