Question 1

The sum of cumulative frequencies in a distribution always equals 1.

Accepted Answer

The sum of cumulative frequencies in a distribution equals the total number of observations, not 1.

Question 2

When comparing two or more samples with different sample sizes,a relative frequency distribution or a percentage distribution should be used.

Accepted Answer

When comparing samples with different sample sizes, it is important to use a relative frequency distribution or a percentage distribution rather than an absolute frequency distribution. This allows for a fair comparison between the samples despite their different sizes, as the data is presented as a proportion of each group rather than raw numbers.

Question 3

In general,grouped frequency distributions should have between 5 and 15 class intervals.

Accepted Answer

This is because having too few or too many intervals can lead to the loss of important data characteristics or overcomplication of the data.

Question 4

The sum of relative frequencies in a distribution always equals 1.

Accepted Answer

This statement is true by definition. The sum of all relative frequencies in a distribution is always equal to 1, as it represents the entire data set.

Question 5

If the values of the seventh and eighth class in a cumulative frequency distribution are the same,we know that there are no observations in the eighth class.

Accepted Answer

In a cumulative frequency distribution, the value of a class represents the upper limit of that class. Therefore, if the seventh and eighth class have the same value, it means that there are no observations between these two limits, including in the eighth class. So, the statement is true.

Question 6

Instruction 2-8
The Stem-and-Leaf display represents the number of times in a year that a random sample of 100 "lifetime" members of a health club actually visited the facility.
 $$\begin{array} { l l } 
\text { Stem } & \text { Leaves } \
\hline
0 & 012222233333344566666667789999 \
1 & 1111222234444455669999 \
2 & 00011223455556889 \
3 & 0000446799 \
4 & 011345567 \
5 & 0077 \
6 & 8 \
7 & 67 \
8 & 3 \
9 & 0247
\end{array}$$
-Referring to Instruction 2-8,________ of the 100 members visited the health club no more than 12 times in a year.

Accepted Answer

The answer of Instruction 2-8
The Stem-and-Leaf display represents the number...

Question 7

Instruction 2-8
The Stem-and-Leaf display represents the number of times in a year that a random sample of 100 "lifetime" members of a health club actually visited the facility.
 $$\begin{array} { l l } 
\text { Stem } & \text { Leaves } \
\hline
0 & 012222233333344566666667789999 \
1 & 1111222234444455669999 \
2 & 00011223455556889 \
3 & 0000446799 \
4 & 011345567 \
5 & 0077 \
6 & 8 \
7 & 67 \
8 & 3 \
9 & 0247
\end{array}$$
-Referring to Instruction 2-8,if a frequency distribution with equal sized classes was made from this data,and the first class was "0 but less than 10",the frequency of the fifth class would be ________.

Accepted Answer

The answer of Instruction 2-8
The Stem-and-Leaf display represents the number...

Question 8

A research analyst was directed to arrange raw data collected on the yield of wheat,ranging from 1 to 5 tonnes per hectare,in a frequency distribution.He should choose 2 as the class interval width.

Accepted Answer

The answer of A research analyst was directed to arrange...

Question 9

Apple Computer,Inc.collected information on the age of their customers.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 data as a proportion of a whole, with the x-axis representing the values and the y-axis representing the percentage. It can be used to study the distribution of data and identify any patterns, trends or gaps in the data. In this case, the age of the customers can be grouped into different categories and the percentage of customers in each category can be plotted on the graph. This would provide a visual representation of the distribution of age among the customers of Apple Computer, Inc.

Question 10

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

Accepted Answer

This statement is true. Relative frequency is calculated by dividing the frequency of each class by the total number of observations. It gives the proportion or percentage of observations in each class.

Question 11

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

Accepted Answer

The percentage distribution can be calculated by dividing each frequency by the total frequency, and then multiplying the result by 100 to get a percentage. This calculation requires the use of the frequency distribution, so the percentage distribution can be constructed directly from it.

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

When the number of observations in a data set increases, the range of values covered also increases, which means more class intervals are needed to group the data effectively.

Question 13

Instruction 2-8
The Stem-and-Leaf display represents the number of times in a year that a random sample of 100 "lifetime" members of a health club actually visited the facility.
 $$\begin{array} { l l } 
\text { Stem } & \text { Leaves } \
\hline
0 & 012222233333344566666667789999 \
1 & 1111222234444455669999 \
2 & 00011223455556889 \
3 & 0000446799 \
4 & 011345567 \
5 & 0077 \
6 & 8 \
7 & 67 \
8 & 3 \
9 & 0247
\end{array}$$
-Referring to Instruction 2-8,if a frequency distribution with equal sized classes was made from this data,and the first class was "0 but less than 10",the cumulative percentage of the next-to-last class would be ________.

Accepted Answer

The answer of Instruction 2-8
The Stem-and-Leaf display represents the number...

Question 14

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

Accepted Answer

Once data is grouped into a frequency distribution, the individual data values are replaced by intervals or categories. Therefore, the original values cannot be determined solely from the frequency distribution.

Question 15

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 16

When constructing a frequency distribution,classes should be selected in such a way that they are of equal width.

Accepted Answer

Classes in a frequency distribution should be of equal width to ensure the data is grouped and presented in a consistent manner. This allows for accurate comparisons and analysis of the data.

Question 17

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 18

Instruction 2-8
The Stem-and-Leaf display represents the number of times in a year that a random sample of 100 "lifetime" members of a health club actually visited the facility.
 $$\begin{array} { l l } 
\text { Stem } & \text { Leaves } \
\hline
0 & 012222233333344566666667789999 \
1 & 1111222234444455669999 \
2 & 00011223455556889 \
3 & 0000446799 \
4 & 011345567 \
5 & 0077 \
6 & 8 \
7 & 67 \
8 & 3 \
9 & 0247
\end{array}$$
-Referring to Instruction 2-8,if a frequency distribution with equal sized classes was made from this data,and the first class was "0 but less than 10",the relative frequency of the last class would be ________.

Accepted Answer

The answer of Instruction 2-8
The Stem-and-Leaf display represents the number...

Question 19

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

Accepted Answer

Class boundaries involve choosing upper and lower limits that define the intervals or classes in a frequency distribution. The selection of these boundaries can be influenced by the preference of the researcher or the purpose of the analysis, making it a highly subjective process.

Question 20

Instruction 2-8
The Stem-and-Leaf display represents the number of times in a year that a random sample of 100 "lifetime" members of a health club actually visited the facility.
 $$\begin{array} { l l } 
\text { Stem } & \text { Leaves } \
\hline
0 & 012222233333344566666667789999 \
1 & 1111222234444455669999 \
2 & 00011223455556889 \
3 & 0000446799 \
4 & 011345567 \
5 & 0077 \
6 & 8 \
7 & 67 \
8 & 3 \
9 & 0247
\end{array}$$
-Referring to Instruction 2-8,if a frequency distribution with equal sized classes was made from this data,and the first class was "0 but less than 10",the class midpoint of the third class would be ________.

Accepted Answer

The answer of Instruction 2-8
The Stem-and-Leaf display represents the number...

Quiz 2: Presenting Data in Tables and Charts

The sum of cumulative frequencies in a distribution always equals 1.

When comparing two or more samples with different sample sizes,a relative frequency distribution or a percentage distribution should be used.

In general,grouped frequency distributions should have between 5 and 15 class intervals.

The sum of relative frequencies in a distribution always equals 1.

If the values of the seventh and eighth class in a cumulative frequency distribution are the same,we know that there are no observations in the eighth class.

A research analyst was directed to arrange raw data collected on the yield of wheat,ranging from 1 to 5 tonnes per hectare,in a frequency distribution.He should choose 2 as the class interval width.

Apple Computer,Inc.collected information on the age of their customers.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.

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

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

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

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

Ogives are plotted at the midpoints of the class groupings.

When constructing a frequency distribution,classes should be selected in such a way that they are of equal width.

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

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