Question 1

A frequency distribution is a grouping of quantitative data into overlapping classes showing the number of observations in each class.

Accepted Answer

A frequency distribution groups quantitative data into non-overlapping classes, showing the number of observations in each class.

Question 2

The midpoint of a class is halfway between the lower and upper limits.

Accepted Answer

This is the definition of the midpoint of a class interval. It is calculated as (lower limit + upper limit) / 2.

Question 3

A cumulative frequency distribution is used when we want to determine how many observations lie above or below certain values.

Accepted Answer

A cumulative frequency distribution adds up the frequency of observations up to a certain value, allowing us to determine how many observations are above or below that value.

Question 4

To construct a pie chart,relative class frequencies are used to graph the "slices" of the pie.

Accepted Answer

Relative class frequencies represent the proportion of the data that falls within each class, so they are used to determine the size of each slice in a pie chart.

Question 5

A small sample of computer operators shows monthly incomes of $1,950,$1,775,$2,060,$1,840,$1,795,$1,890,$1,925,and $1,810. What are these ungrouped numbers called?
A)Histograms
B)Class limits
C)Class frequencies
D)Raw data

Accepted Answer

The ungrouped numbers are called raw data. Raw data refers to the actual measurements or observations collected in a study or survey before they are organized, summarized, or analyzed.

Question 6

A class interval can be determined by subtracting the lower limit of a class from the lower limit of the next higher class.

Accepted Answer

This statement is true. The difference between the lower limit of a class and the lower limit of the next higher class gives the width or size of the class interval.

Question 7

To convert a frequency distribution to a relative frequency distribution,divide each class frequency by the number of classes.

Accepted Answer

To convert a frequency distribution to a relative frequency distribution, divide each class frequency by the total frequency (sum of all class frequencies).

Question 8

In a bar chart,the heights of the bars represent the frequencies in each class.

Accepted Answer

In a bar chart, the heights of the bars represent the frequencies or values in each class.

Question 9

A pie chart is similar to a relative frequency distribution.

Accepted Answer

Both a pie chart and a relative frequency distribution display the proportion or percentage of each category within a data set. However, a pie chart uses visual depiction while a relative frequency distribution uses numerical representation.

Question 10

When data are collected using a quantitative,ratio variable,what is true about a frequency distribution that summarizes the data?
A)Upper and lower class limits must be calculated.
B)A pie chart can be used to summarize the data.
C)The number of classes is equal to the number of variable values.
D)The "5 to the k rule" can be applied.

Accepted Answer

When data are collected using a quantitative, ratio variable, upper and lower class limits must be calculated to create a frequency distribution. This helps to identify the range and distribution of the data. Option B is incorrect as a pie chart is typically used to summarize qualitative data, not quantitative data. Option C is incorrect as the number of classes depends on the range of the data and the desired level of detail, not the number of variable values. Option D is incorrect as the "5 to the k rule" applies to creating histograms, not frequency distributions.

Question 11

When data are collected using a qualitative,nominal variable,what is true about a frequency table that summarizes the data?
A)The upper and lower class limits must be calculated.
B)A pie chart can be used to summarize the data.
C)The number of classes is equal to the number of variable's values plus 2.
D)The "5 to the k rule" can be applied.

Accepted Answer

Since the variable is qualitative and nominal, the data cannot be quantified or ordered in a meaningful way. Therefore, a frequency table can only provide the count or percentage of each category, and a pie chart is the best way to visually summarize the proportions of each category. The other options are not applicable because they pertain to quantitative or ordinal data.

Question 12

A frequency table for qualitative data has class limits.

Accepted Answer

A frequency table for qualitative data uses categories or class intervals rather than numerical class limits, which are used for quantitative data.

Question 13

To summarize the gender of students attending a college,the number of classes in a frequency table depends on the number of students.

Accepted Answer

The number of classes in a frequency table is determined by the number of categories being observed, not the number of students. In this case, the categories would be male and female.

Question 14

When data are collected using a qualitative,nominal variable (e.g.,male or female),what is true about a frequency table that summarizes the data?
A)The upper and lower class limits must be calculated.
B)Class midpoints can be computed.
C)The number of classes corresponds to the number of a variable's values.
D)The "2 to the k rule" can be applied.

Accepted Answer

Since the data is nominal, there are no numerical values to calculate class limits, midpoints or apply the "2 to the k rule". The frequency table will simply list the categories of the variable and the corresponding frequencies, with the number of classes equal to the number of unique values in the variable.

Question 15

In a bar chart,the horizontal axis is usually labeled with the values of a qualitative variable.

Accepted Answer

In a bar chart, the horizontal axis (x-axis) is typically used to display the categories of a qualitative (or categorical) variable, while the vertical axis (y-axis) shows the values that correspond to those categories.

Question 16

To convert a frequency distribution to a relative frequency distribution,divide each class frequency by the sum of the class frequencies.

Accepted Answer

This is a correct statement. To convert a frequency distribution to a relative frequency distribution, we divide each class frequency by the sum of the class frequencies. This gives us the proportion or percentage of observations that fall into each class.

Question 17

A pie chart shows the relative frequency in each class.

Accepted Answer

A pie chart displays the relative frequency or proportion of each category, often represented as wedges of a circle.

Question 18

In frequency distributions,classes are mutually exclusive if each individual,object,or measurement is included in only one category.

Accepted Answer

In frequency distributions, it is important for classes to be mutually exclusive, meaning that each individual, object, or measurement should only fall into one category. This ensures that the data is not double-counted and helps to accurately represent the distribution of the data.

Question 19

A frequency polygon is a very useful graphic technique when comparing two or more distributions.

Accepted Answer

A frequency polygon plots the frequency of a variable on the y-axis against the value of the variable on the x-axis. This allows for easy comparison between multiple distributions.

Question 20

Monthly commissions of first-year insurance brokers are $1,270,$1,310,$1,680,$1,380,$1,410,$1,570,$1,180,and $1,420. These figures are referred to as
A)a histogram.
B)raw data.
C)a frequency distribution.
D)a frequency polygon.

Accepted Answer

These figures represent raw data, which is the original data collected in a study before any analysis, summarization, or manipulation.

Quiz 2: Describing Data: Frequency Tables, Frequency Distributions, and Graphic Presentation