Question 1

A relative frequency is typically used with smaller,but not larger,data sets.

Accepted Answer

Relative frequency can be used with both small and large data sets to show the proportion of each category relative to the total number of data points.

Question 2

A cumulative frequency distribution is the sum of frequencies across a series of intervals.

Accepted Answer

A cumulative frequency distribution is indeed the sum of frequencies across a series of intervals. It shows the running total of frequencies up to a certain point or interval.

Question 3

To summarize relative percent data,a pie chart can be a good choice to display the data.

Accepted Answer

Pie charts are a good choice to display relative percent data because they show the proportion of each category in relation to the whole. This makes it easier for viewers to compare the different categories and see how they relate to each other.

Question 4

A circular graph that displays the relative percentage of a frequency distribution into sectors is called a scatter gram.

Accepted Answer

A circular graph that displays the relative percentage of a frequency distribution into sectors is called a pie chart, not a scatter gram.

Question 5

Cumulative percent data can be summarized using an ogive.

Accepted Answer

An ogive is a graph that represents cumulative frequency or cumulative percent data. So, cumulative percent data can be summarized using an ogive.

Question 6

Whether you cumulate a frequency distribution from the bottom up or the top down depends on how you want to discuss the data.

Accepted Answer

Cumulating a frequency distribution from the bottom up is also known as the cumulative frequency method, and it adds up the frequencies starting from the lowest value. Cumulating from the top down is referred to as the inverse cumulative frequency method, and it starts with the highest value. The choice of method depends on the type of analysis and presentation of data that is desired.

Question 7

The corresponding percentile of a given percentile point is the percentile rank of that score.

Accepted Answer

This statement is true. The percentile rank represents the percentage of scores that fall below a given score, while the percentile represents the actual score that falls below a given percentile rank. Therefore, the corresponding percentile of a given percentile point is the percentile rank of that score.

Question 8

A frequency polygon is a dot-and-line graph where the dot is the upper class boundary of each interval and the line connects each dot.

Accepted Answer

A frequency polygon is a graphical representation of the distribution of a dataset. It is typically constructed by plotting the midpoints of the intervals (not the upper class boundaries) on the x-axis and connecting these points with straight lines.

Question 9

The percentile rank of a score is the percentage of scores with values that fall below a specified score in a distribution.

Accepted Answer

This is a correct definition of percentile rank.

Question 10

The sum of the frequencies for a distribution is 100.This means that fewer than 100 persons were counted.

Accepted Answer

This statement is false. The sum of frequencies for a distribution does not necessarily indicate the number of individuals counted. It just represents the total number of occurrences or observations within the distribution. It is possible that the frequency counts are greater than 100 if some individuals or events are counted multiple times.

Question 11

Twelve percent of students scored at or below a failing grade on an exam.A percentile rank distribution would be appropriate to summarize this outcome.

Accepted Answer

A percentile rank distribution would be appropriate to summarize the outcome of the exam scores with respect to the percentage of students who scored at or below a failing grade.

Question 12

In a bar chart,each class or category is represented by a rectangle and each rectangle is separated (does not touch)along the x-axis.

Accepted Answer

This statement is true. In a bar chart, each category or class is represented by a rectangular bar, and each bar is separated from the others along the x-axis. This allows viewers to easily distinguish between different categories and compare their values.

Question 13

A histogram is used to summarize grouped data.

Accepted Answer

A histogram is a graphical representation of frequencies using bars where the data is grouped into intervals (or bins) and the height of each bar represents the frequency or count of data points within that interval. It is commonly used to summarize and display the distribution of continuous or discrete data.

Question 14

Bar charts are used to summarize discrete and categorical data.

Accepted Answer

Bar charts are commonly used to display and summarize categorical data by displaying the frequency or proportion of each category.

Question 15

Relative frequencies sum to the total frequency count.

Accepted Answer

Relative frequencies sum to 1 (or 100% if expressed as a percentage) because they represent the proportion of the total frequency count for each category.

Question 16

A stem-and-leaf display retains the value of each data point.

Accepted Answer

A stem-and-leaf display partitions each data point into a stem (usually the leftmost digits) and a leaf (usually the rightmost digit), so every value is retained, just in a different format.

Question 17

A frequency polygon,but not an ogive,can be used to summarize cumulative percent distributions.

Accepted Answer

A frequency polygon is a line graph that shows the frequency of data within certain intervals. It can show the shape of the distribution of data but does not include cumulative values. On the other hand, an ogive is a graph that shows cumulative values and can be used to summarize cumulative percent distributions. Therefore, a frequency polygon cannot be used to summarize cumulative percent distributions.

Question 18

A histogram is basically a bar chart in which the bars do not touch.

Accepted Answer

In a histogram, the bars do touch each other, which indicates the continuous nature of the data being represented.

Question 19

A percentile rank is a cumulative percentage distribution summed from the bottom up.

Accepted Answer

A percentile rank is a position-based statistic that shows the percentage of scores that are equal to or lower than a particular score. It is calculated by dividing the number of scores that are equal to or lower than a particular score by the total number of scores, then multiplying by 100. Therefore, it is a cumulative percentage distribution summed from the bottom up.

Question 20

Percentages range from 0% to 100% and can never be negative.

Accepted Answer

Percentages are always expressed as a positive value between 0% and 100%. Negative percentage values do not exist.

Quiz 2: Summarizing Data: Frequency Distributions in Tables and Graphs