Question 1

Ogives are plotted at the midpoints of the class groupings.

Accepted Answer

Ogives are plotted at the endpoints of the class groupings, not the midpoints.

Question 2

The relative frequency is the frequency in each class divided by the total number of observations.

Accepted Answer

The statement correctly defines relative frequency as the frequency of a class divided by the total number of observations.

Question 3

The percentage distribution cannot be constructed from the frequency distribution directly.

Accepted Answer

The percentage distribution can be constructed by dividing each frequency by the total number of observations and multiplying by 100.

Question 4

Determining the class boundaries of a frequency distribution is highly subjective.

Accepted Answer

Class boundaries are often determined based on the scale of measurement and the desired level of precision, which can be subjective and thus vary from person to person.

Question 5

Apple Computer, Inc.collected information on the age of their customers.Suppose the youngest customer was 12 and the oldest was 72.To study the distribution of the age among its customers, it can use a Pareto chart.

Accepted Answer

A Pareto chart is used to display the frequency or relative frequency of a set of data in descending order of magnitude. It is most commonly used for analyzing the frequency of defects, errors, or problems in a process. While it is possible to create a Pareto chart for age data, it is not the most appropriate or useful way to visualize the distribution of ages among Apple's customers. A histogram would be a more appropriate choice for this type of data.

Question 6

Apple Computer, Inc.collected information on the age of their customers.Suppose the youngest customer was 12 and the oldest was 72.To study the percentage of their customers who are below a certain age, it can use an ogive.

Accepted Answer

An ogive is a graph that represents the cumulative frequency distribution of a set of data, and it can be used to study the percentage of customers who are below a certain age. Therefore, the statement is true.

Question 7

Apple Computer, Inc.collected information on the age of their customers.Suppose the youngest customer was 12 and the oldest was 72.To study the distribution of the age among its customers, it can use a percentage polygon.

Accepted Answer

A percentage polygon is a graph used to show the percentage distribution of data. It can be used to display the distribution of ages among Apple Computer, Inc.'s customers, given the range of ages provided.

Question 8

The stem-and-leaf display is often superior to the frequency distribution in that it maintains the original values for further analysis.

Accepted Answer

The stem-and-leaf display preserves the individual data points and shows their relative frequency, whereas the frequency distribution only shows binned data and can hide important information. Therefore, the stem-and-leaf display is often considered superior for detailed analysis of the data.

Question 9

If you wish to construct a graph of a relative frequency distribution, you would most likely construct an ogive first.

Accepted Answer

To construct a graph of a relative frequency distribution, you would most likely construct a histogram or a frequency polygon first, not an ogive. An ogive is used to display a cumulative frequency distribution.

Question 10

An ogive is a cumulative percentage polygon.

Accepted Answer

This statement is true. An ogive shows the cumulative frequency or percentage of data in a distribution, and it is often graphed as a line or polygon.

Question 11

Apple Computer, Inc.collected information on the age of their customers.Suppose the youngest customer was 12 and the oldest was 72.To study the distribution of the age among its customers, it is best to use a pie chart.

Accepted Answer

A pie chart is not suitable for displaying the distribution of ages as it is primarily used for displaying categorical data. A histogram or a frequency polygon would be a better option for displaying the distribution of ages in this case.

Question 12

The larger the number of observations in a numerical data set, the larger the number of class intervals needed for a grouped frequency distribution.

Accepted Answer

As the number of observations increases, the range of values may also increase, requiring more class intervals to effectively summarize the data.

Question 13

Histograms are used for numerical data while bar charts are suitable for categorical data.

Accepted Answer

Histograms display numerical data by grouping it into intervals, while bar charts represent categorical data by using distinct bars to show the count or percentage of each category.

Question 14

Percentage polygons are plotted at the boundaries of the class groupings.

Accepted Answer

Percentage polygons are plotted using the percentage values of each class interval, not at the boundaries of the class groupings.

Question 15

A good choice for the number of class groups to use in constructing frequency distribution is to have at least 5 but no more than 15 class groups.

Accepted Answer

Having too few class groups can result in insufficient information and having too many class groups can result in overly detailed and confusing data. A range of 5 to 15 class groups generally provides a good balance between information and simplicity.

Question 16

A side-by-side bar chart is two histograms plotted side-by-side.

Accepted Answer

A side-by-side bar chart is used to compare two sets of data across categories by displaying bars for each category next to each other, while histograms are used to show distributions of a single variable and typically display bars that represent the frequency of data points within certain ranges.

Question 17

The main principle behind the Pareto chart is the ability to separate the "vital few" from the "trivial many."

Accepted Answer

The Pareto chart is based on the idea that roughly 80% of the effects come from 20% of the causes, so it helps to identify the most significant factors or problems contributing to a particular issue. This is known as the Pareto principle, and it is represented graphically through a bar chart with the bars arranged in order from tallest to shortest, allowing users to visually distinguish the most important factors from the least important ones.

Question 18

The original data values cannot be determined once they are grouped into a frequency distribution table.

Accepted Answer

Once the data values are grouped into categories and represented in a frequency distribution table, individual data points cannot be inferred.

Question 19

A Walmart store in a small town monitors customer complaints and organizes these complaints into six distinct categories.Over the past year, suppose the company has received 534 complaints.One possible graphical method for representing these data would be a Pareto chart.

Accepted Answer

A Pareto chart is a graphical representation of the relative frequency or size of problems in descending order of importance. Therefore, it would be an appropriate method for organizing and displaying the six categories of customer complaints at the Walmart store.

Question 20

A histogram can have gaps between the bars, whereas bar charts cannot have gaps.

Accepted Answer

Both histograms and bar charts can have gaps between the bars; however, in a histogram, gaps usually indicate a class interval with no occurrences, while in bar charts, gaps are used to visually separate different categories.

Quiz 2: Organizing and Visualizing Variables