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 formula for relative frequency: $$	ext{Relative frequency} = \frac{	ext{frequency}}{	ext{sum of all frequencies}}$$, what is the relative frequency of a category with 8 occurrences in a dataset with a total of 40 observations?

Accepted Answer

$$0.20$$

Question 3

Which type of graph is most appropriate for comparing the frequencies of different categories in qualitative data?

Accepted Answer

Bar graph

Question 4

A pie chart is best used when:

Accepted Answer

You want to show the proportion of each category relative to the whole.

Question 5

Which of the following statements about histograms is TRUE?

Accepted Answer

The rectangles in a histogram touch each other, representing continuous data.

Question 6

Suppose you have the following data for the number of siblings in a class: 2, 1, 4, 1, 7, 0, 2, 1, 2, 2. What is the frequency of students with 2 siblings?

Accepted Answer

4

Question 7

When constructing a frequency distribution for continuous data, what is the purpose of using class intervals?

Accepted Answer

To group a large number of different data values into manageable categories.

Question 8

A bar graph is constructed by:

Accepted Answer

Labeling each category of data on one axis and drawing rectangles whose heights represent the frequency or relative frequency.

Question 9

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

Accepted Answer

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

Question 10

If a distribution is described as 'skewed right,' what does this mean?

Accepted Answer

The tail to the right of the peak is longer than the tail to the left of the peak.

Question 11

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

Accepted Answer

Small sets of quantitative data where each value can be plotted individually.

Question 12

Which of the following best describes a Pareto chart?

Accepted Answer

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

Question 13

In a stem-and-leaf plot, what does each 'leaf' represent?

Accepted Answer

The rightmost digit of a data value.

Question 14

Which of the following is NOT a valid reason to use relative frequencies instead of frequencies when comparing two groups?

Accepted Answer

Relative frequencies are always larger than frequencies.

Question 15

A bell-shaped distribution is characterized by:

Accepted Answer

The highest frequency occurring in the middle and frequencies tailing off to the left and right.

Question 16

Suppose you are given unemployment rates for all 50 states. Which graphical method would be most appropriate to display the distribution of these rates?

Accepted Answer

Histogram

Question 17

When constructing a frequency distribution for continuous data, what is the lower class limit of the class 25 to 34.9?

Accepted Answer

$$25$$

Question 18

Which of the following is a correct step in constructing a stem-and-leaf plot?

Accepted Answer

Write the stems vertically in ascending order.

Question 19

A frequency polygon is constructed by:

Accepted Answer

Plotting points at the midpoints of each class interval and connecting them with straight lines.

Question 20

Which of the following is NOT a characteristic of a uniform distribution?

Accepted Answer

The frequency of each value is highest in the middle.

Organizing and Displaying Data in Statistics: Tables and Graphs

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