Question 1

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

Accepted Answer

Class boundaries can vary depending on the preferences of the person creating the frequency distribution. There is no set rule for determining class boundaries, making it a subjective process.

Question 2

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

Accepted Answer

Percentage polygons are plotted at the midpoints of the class intervals, not at the boundaries of the class groupings.

Question 3

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

Accepted Answer

When data is grouped into a frequency distribution table, multiple values are combined into a single category. Therefore, the original data values are lost and cannot be determined.

Question 4

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 display the relative frequencies or percentages of a set of data. Since the age range of Apple's customers is known, it is possible to create a frequency table and use a percentage polygon to study the distribution.

Question 5

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

Accepted Answer

A side-by-side bar chart is used to display and compare the frequency, count, or proportion of different categories or groups side by side, while histograms are used to show the distribution of a continuous data set, displaying the frequencies of different ranges of values.

Question 6

An ogive is a cumulative percentage polygon.

Accepted Answer

An ogive is a graph that represents cumulative frequency distribution. It plots the cumulative percentage of data against the upper or lower class boundary, forming a cumulative percentage polygon.

Question 7

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

Accepted Answer

This is the correct definition of relative frequency, as it is the frequency of a particular class divided by the total number of observations.

Question 8

One of the advantages of a pie chart is that it clearly shows that the total of all the categories of the pie adds to 100%.

Accepted Answer

This is one of the primary uses of a pie chart, to clearly display the proportions of each category in relation to the whole, which should always add up to 100%.

Question 9

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 appropriate for displaying the distribution of age as it only shows relative proportions of different categories. A histogram or a frequency polygon would be more appropriate for displaying age distribution.

Question 10

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

This is true as more observations require a larger number of intervals to accurately represent the data.

Question 11

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

Accepted Answer

Histograms show the distribution of numerical data, while bar charts are used to represent categorical data.

Question 12

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 retains the original values of the data, which can be useful for further analysis such as calculating measures of central tendency or dispersion. In contrast, the frequency distribution only shows the count or proportion of data falling within each interval or category, which may obscure important details about the data.

Question 13

Ogives are plotted at the midpoints of the class groupings.

Accepted Answer

Ogives are cumulative frequency graphs and are plotted at the upper boundaries of the class intervals, not at the midpoints.

Question 14

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

Accepted Answer

A histogram represents the frequency distribution of continuous data, and its bars touch each other to indicate the continuous nature of the data. Bar charts, on the other hand, represent categorical data with discrete values, and the bars can be separated by gaps to emphasize their distinct categories.

Question 15

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 graph is often used for cumulative frequency distributions, which is a way of showing how many observations fall below a certain value or range of values. In this case, Apple could use an ogive to show what percentage of their customers are below certain ages, such as 30, 40, or 50.

Question 16

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, a histogram or a frequency polygon would be more appropriate than an ogive. An ogive is used to construct a cumulative frequency distribution.

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 Pareto principle, which states that 80% of the effects come from 20% of the causes. The chart helps to identify and prioritize the most significant factors or problems that contribute to a particular outcome. This is achieved by separating the "vital few" from the "trivial many" through a descending bar graph and a cumulative line graph.

Question 18

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

Accepted Answer

The percentage distribution can be directly constructed from the frequency distribution by calculating the percentage of each category's frequency relative to the total frequency.

Question 19

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 for studying the frequency of occurrence of different categories in a dataset. It is not suitable for studying the distribution of continuous numerical data like age. A histogram or a box-and-whisker plot would be more appropriate for studying the distribution of age among Apple's customers.

Question 20

A Walmart store 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 method that is used to represent the relative distribution of different categories in a given dataset. It is often used by companies to identify the most significant sources of complaints or problems, so that they can focus their efforts on addressing them. In this case, a Walmart store has received 534 complaints over the past year, and these complaints have been categorized into six distinct categories. A Pareto chart would be an appropriate tool to represent these data, since it would allow the company to identify which categories are responsible for the majority of the complaints. A Pareto chart is a graphical representation of data that ranks categories in descending order of frequency or size. It is commonly used to identify the most significant categories in a dataset or to focus on the most important problems or issues that need to be addressed. Therefore, a Pareto chart would be an appropriate graphical method for representing customer complaints in six categories at a Walmart store over the past year.

Quiz 2: Organizing and Visualizing Variables