Question 1

A pie chart is a segmented circle that portrays the categories and relative sizes of some quantitative variable.

Accepted Answer

False

Question 2

Exhibit 2-1.An auto parts chain asked customers to complete a survey rating the chain's customer service as average,above average,or below average.The following shows the results from the survey:  Refer to Exhibit 2-1.A rating of Average or Above Average accounted for what number of responses to the survey?
A)3
B)7
C)8
D)10

Accepted Answer

The rating of Average or Above Average includes the responses of Above Average (5) and Average (3), which gives a total of 8 responses.

Question 3

For which of the following data sets will a pie chart be most useful?
A)Heights of high school freshmen
B)Ambient temperatures in the U.S.Capitol Building
C)Percentage of net sales by product for Lenovo in 2011
D)Growth rates of firms in a particular industry

Accepted Answer

A pie chart would be most useful for displaying the percentage breakdown of net sales by product for Lenovo in 2011, as it allows for easy visualization of each product's proportion of total sales.

Question 4

A stem-and-leaf diagram is useful in that it gives an overall picture of where quantitative data are centered and how the data are dispersed from the center.

Accepted Answer

This statement is true. A stem-and-leaf diagram allows us to quickly see the range of values, the frequency of each value, and the overall shape of the distribution. We can also use it to identify outliers and clusters within the data.

Question 5

The percent frequency of a category equals the frequency of the category multiplied by 100%.

Accepted Answer

The answer of The percent frequency of a category equals...

Question 6

A scatterplot is a graphical tool that helps determine whether or not two quantitative variables are related.

Accepted Answer

This statement is true. Scatterplots are commonly used to visually explore relationships between two quantitative variables by plotting the values of each variable along the x and y-axes and looking for patterns or trends in the resulting points.

Question 7

Exhibit 2-1.An auto parts chain asked customers to complete a survey rating the chain's customer service as average,above average,or below average.The following shows the results from the survey:  Refer to Exhibit 2-1.The proportion of customers that felt the customer service was average is closest to ______.
A)0.20
B)0.33
C)0.46
D)0.53

Accepted Answer

The proportion of customers that felt the customer service was average is the percentage of responses that selected "average". From the table, we see that there were a total of 18 responses, and 6 of them selected "average". Therefore, the proportion is 6/18 = 0.33 or approximately 33%.

Question 8

A bar chart depicts the frequency or relative frequency of each category of qualitative data as a bar rising vertically from the horizontal axis.It is also acceptable for the bar to extend horizontally from the vertical axis.

Accepted Answer

A bar chart can have bars rising vertically or extending horizontally from the vertical axis depending on the design and format of the chart.

Question 9

A polygon connects a series of neighboring points where each point represents the midpoint of a particular class and its associated frequency or relative frequency.

Accepted Answer

This statement describes a polygon frequency graph.

Question 10

For quantitative data,a cumulative frequency distribution records the number of observations that fall below the upper limit of each class.

Accepted Answer

This statement is true.

Question 11

When constructing a scatterplot for two quantitative variables,we usually refer to one variable as x and another one as y.Typically,we graph x on the vertical axis and y on the horizontal axis.

Accepted Answer

This statement is false. Typically, we graph y on the vertical axis and x on the horizontal axis.

Question 12

Frequency distributions may be used to describe which of the following types of data?
A)Nominal and ordinal data only
B)Nominal and interval data only
C)Nominal,ordinal,and interval data only
D)Nominal,ordinal,interval,and ratio data

Accepted Answer

Frequency distributions can be used to describe all types of data, including nominal, ordinal, interval, and ratio data.

Question 13

To approximate the width of a class in the creation of a bar chart,we may use this formula:  .

Accepted Answer

The formula to approximate the width of a class in the creation of a bar chart is not provided in the question. Therefore, the answer is false.

Question 14

For quantitative data,a cumulative relative frequency distribution records the proportion (fraction)of values that fall below the upper limit of each class.

Accepted Answer

This is true for cumulative relative frequency distributions.

Question 15

For both qualitative and quantitative data,what is the difference between the relative frequency and the percent frequency?
A)The relative frequency equals the percent frequency multiplied by 100.
B)The percent frequency equals the relative frequency multiplied by 100.
C)As opposed to the relative frequency,the percent frequency is divided by the number of observations in the data set.
D)As opposed to the percent frequency,the relative frequency is divided by the number of observations in the data set.

Accepted Answer

The percent frequency is calculated by dividing the frequency of a particular category by the total number of observations in the data set and multiplying by 100. The relative frequency is also calculated the same way but without multiplying by 100. Therefore, the percent frequency equals the relative frequency multiplied by 100.

Question 16

A frequency distribution for qualitative data groups this data into classes called intervals and records the total number of observations in each class.

Accepted Answer

A frequency distribution for qualitative data groups data into categories, not intervals, and records the total number of observations in each category.

Question 17

An ogive is a graph that plots the cumulative frequency (or the cumulative relative frequency)of each class above the lower limit of the corresponding class.

Accepted Answer

The answer of An ogive is a graph that plots...

Question 18

In order to summarize qualitative data,a useful tool is a _________.
A)Histogram
B)Frequency distribution
C)Stem-and-leaf diagram
D)All of the above

Accepted Answer

A histogram and stem-and-leaf diagram are both tools for summarizing quantitative data, whereas a frequency distribution is a tool for summarizing both qualitative and quantitative data. Therefore, the best choice for summarizing qualitative data is a frequency distribution, making choice B the correct answer.

Question 19

The relative frequency of a category is calculated by dividing the category's frequency by the total number of observations.

Accepted Answer

This statement is true. Relative frequency is a commonly used term in statistics and is calculated by dividing the frequency of a category by the total number of observations.

Question 20

A histogram is a series of rectangles where the width and height of each rectangle represent the frequency (or relative frequency)and the width of the class,respectively.

Accepted Answer

The answer of A histogram is a series of rectangles...

Quiz 2: Tabular and Graphical Methods