Question 1

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

Accepted Answer

A table listing 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 12 occurrences in a dataset with a total of 60 observations?

Accepted Answer

$$\frac{12}{60} = 0.2$$

Question 3

When constructing a bar graph for categorical data, which axis typically represents the categories?

Accepted Answer

The horizontal axis

Question 4

A Pareto chart is most useful when you want to:

Accepted Answer

Display categories in decreasing order of frequency or relative frequency.

Question 5

Suppose you want to compare the number of children under 18 living with one parent by age group. Which type of graph would be most appropriate?

Accepted Answer

Side-by-side bar graph

Question 6

Which of the following statements about pie charts is correct?

Accepted Answer

Each sector's area is proportional to the frequency of the category it represents.

Question 7

When organizing discrete quantitative data into a frequency distribution, what is the first step?

Accepted Answer

List all possible values of the variable.

Question 8

A histogram differs from a bar graph in that:

Accepted Answer

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

Question 9

Given the following class limits for a continuous variable: 25-34, 35-44, 45-54, what is the width of each class?

Accepted Answer

$$35 - 25 = 10$$

Question 10

If a dataset of unemployment rates by state is grouped into intervals of 1%, what type of graph would best display the frequency distribution?

Accepted Answer

Histogram

Question 11

Which of the following best describes a uniform distribution?

Accepted Answer

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

Question 12

A stem-and-leaf plot is constructed by:

Accepted Answer

Splitting each data value into a stem (all but the rightmost digit) and a leaf (the rightmost digit).

Question 13

Which graph is most appropriate for displaying the number of siblings for each student in a class?

Accepted Answer

Dot plot

Question 14

If a histogram of unemployment rates shows the highest frequency in the middle and frequencies tail off to both sides, what is the shape of the distribution?

Accepted Answer

Bell-shaped (symmetric)

Question 15

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

Accepted Answer

Relative frequencies are always larger than frequencies.

Question 16

When constructing a frequency polygon, what is plotted on the horizontal axis?

Accepted Answer

The midpoints of each class interval

Question 17

A dataset of exam scores is grouped into intervals: 50-59, 60-69, 70-79, 80-89, 90-99. If the interval 70-79 has the highest frequency, but the tail to the right is longer than the tail to the left, the distribution is:

Accepted Answer

Skewed right

Question 18

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

Accepted Answer

Histograms are used for quantitative data; bar graphs are used for qualitative data.

Question 19

If you are given a dataset with a large number of different discrete values, which method is best for organizing the data?

Accepted Answer

Group the data into classes using intervals of numbers.

Question 20

Which of the following is true about open-ended classes in a frequency distribution?

Accepted Answer

The last class has no upper class limit.

Organizing and Displaying Data in Statistics

Guida di studio - Domande di pratica

Study guide - Flashcard