Question 1

A stem and leaf plot is a data plot that uses part of a data value as the stem and part of the data value as
the leaf to form groups or classes.

Accepted Answer

This statement is true. A stem and leaf plot is a type of data plot used to organize and display numerical data. The stem represents the leading digit(s) of a data point and the leaf represents the trailing digit(s). The stems are listed in one column, and the leaves for each stem are listed in a row. This helps to quickly identify the distribution of the data and any patterns or outliers.

Question 2

The larger the sample size, the larger the relative frequencies.

Accepted Answer

The relative frequencies represent the proportion of occurrences in the sample, therefore they should become more stable and closer to the true population proportions as the sample size increases, resulting in smaller relative frequencies.

Question 3

What is the midpoint of the class 4-15?
A)4
B)9.5
C)4 and 15
D)9.5 and 11

Accepted Answer

To find the midpoint of a class, we add the lower limit and upper limit and divide by 2. Therefore, midpoint = (4+15)/2 = 9.5. Therefore, the best choice is B.

Question 4

What is the lower class limit in the class 13-17?
A)15
B)17
C)13
D)12.5

Accepted Answer

The lower class limit is the smallest possible value that fits within a class interval. For the class 13-17, the smallest possible value is 13, so 13 is the lower class limit.

Question 5

Which of the following should not be done when constructing a frequency distribution?
A)select the number of classes desired
B)find the range
C)use a class width with an even number
D)use classes that are mutually exclusive

Accepted Answer

Using a class width with an even number can result in overlapping classes. It is best to use a class width with an odd number to ensure mutually exclusive classes. A, B, and D are all correct steps when constructing a frequency distribution.

Question 6

The rate of mortality of children is very high in the first weeks of life.It then decreases rapidly until 1 or
2 years of age and then increases slowly into the teen years.In this situation one should construct relative
frequency distributions (per year of age) with narrow class widths during the first year of life so as to
exhibit the quickly changing mortality rate.

Accepted Answer

The statement is true. Narrow class widths will allow us to show the rapidly changing mortality rate in the first year of life.

Question 7

One disadvantage of pie charts is that it is difficult to visually compare 2 frequency distributions.Plotting
relative frequency distributions (polygons or ogives) on the same axes is usually more informative.

Accepted Answer

This is because pie charts represent proportions of a whole rather than raw data, which makes it challenging to compare two sets of different raw data directly. Alternatively, plotting relative frequency distributions using polygons or ogives on the same axes can be more useful as each distribution has its line, making comparisons and contrasts more comfortable.

Question 8

What are the boundaries of the class 1.87-3.43?
A)1.9-3.4
B)1.87-3.43
C)1.879-3.439
D)1.865-3.435

Accepted Answer

The boundaries of a class interval are determined by extending the class limits to the next possible value within the measurement scale used, without overlapping into the next class. For a class interval of 1.87-3.43, the lower boundary is slightly less than 1.87 and the upper boundary is slightly more than 3.43, making 1.865-3.435 the correct boundaries to ensure no value is excluded and there's no overlap with adjacent classes.

Question 9

What are the boundaries of the class 4-18?
A)4
B)14
C)4 and 18
D)3.5 and 14.5

Accepted Answer

Class 4-18 includes all numbers between 4 and 18, but not including 4 and 18 themselves. Therefore, the boundaries of the class are 3.5 (the number right before 4) and 14.5 (the number right after 14). Choice D includes both of these values and is therefore the correct answer.

Question 10

In order to graphically compare two frequency distributions, one should use relative frequency
distributions in order to take differing sample sizes into account.

Accepted Answer

Relative frequency distributions adjust for sample size by expressing the frequency of each category as a proportion of the total number of observations in the sample. This makes it easier to compare distributions with different sample sizes.

Question 11

Using the class 23-35, what is the upper class boundary?
A)35
B)29
C)35.5
D)23

Accepted Answer

The upper class boundary can be calculated by adding 0.5 to the upper limit of the class interval. In this case, the upper limit is 35, so the upper class boundary would be 35.5.

Question 12

Find the class with the least number of data values.
A)70
B)90
C)60
D)40

Accepted Answer

The answer of  Find the class with the least...

Question 13

What would be the boundaries on the average age for high school graduates if they were reported to be 18 years old?
A)17.5-18.5 years old
B)17.5-19.5 years old
C)17.6-18.6 years old
D)17.5-19 years old

Accepted Answer

The average age for high school graduates is typically around 18 years old, considering that most students start kindergarten at age 5 and complete 12 grades by around age 18. The boundary of 17.5-18.5 years old allows for a six-month margin before or after their 18th birthday, which is a reasonable range given the typical age distribution of high school graduates.

Question 14

Thirty students recorded the colours of their eyes, choosing from the colours brown, blue, green, hazel, and black.This data can be appropriately summarized in a
A)Open-ended distribution
B)Categorical frequency distribution
C)Grouped frequency distribution
D)Upper boundary

Accepted Answer

Since the data deals with different categories of eye colours, the most appropriate summary would be a categorical frequency distribution. This would allow us to see the frequency of each category (brown, blue, green, hazel, and black) and the overall distribution of eye colours among the students.

Question 15

Find the class with the greatest number of data values.
A)70
B)90
C)60
D)40

Accepted Answer

The answer of  Find the class with the greatest...

Question 16

For the class 10-18, the upper class limit is
A)9
B)10
C)18
D)19

Accepted Answer

The upper class limit is defined as the highest value that can fall within a class interval. In this case, since the class is from 10 to 18, the highest value that can fall within this range is 18. Therefore, the correct answer is C.

Question 17

What is the midpoint of the classes 13.5-17.3?
A)13.4
B)15.4
C)17.3
D)14.3

Accepted Answer

To find the midpoint of a class, add the lower and upper limits of the class and divide by 2.
(13.5 + 17.3)/2 = 15.4

Question 18

What is the lower class limit in the class -7 to 14
A)-7
B)3.5
C)14
D)-7.5

Accepted Answer

The lower class limit is the smallest possible value in a class interval. In this case, the smallest possible value is -7, so the answer is A.

Question 19

For the numbers -5, -2, -7, and 0, which of the following that includes all four is a good class?
A)-8 to 1
B)-5 to 1
C)-7 to 0
D)-7 to 1

Accepted Answer

The answer of For the numbers -5, -2, -7, and...

Question 20

Greg wants to construct a frequency distribution for the political affiliation of the employees at Owen's Hardware Store.What type of distribution should he use?
A)ungrouped
B)grouped
C)categorical
D)cumulative

Accepted Answer

Categorical distribution is used for data that can be divided into specific categories, such as political affiliation, which does not involve numerical values but rather names or labels of groups.

Quiz 2: Frequency Distributions and Graphs

A stem and leaf plot is a data plot that uses part of a data value as the stem and part of the data value as the leaf to form groups or classes.

The larger the sample size, the larger the relative frequencies.

What is the midpoint of the class 4-15?

What is the lower class limit in the class 13-17?

Which of the following should not be done when constructing a frequency distribution?

One disadvantage of pie charts is that it is difficult to visually compare 2 frequency distributions.Plotting relative frequency distributions (polygons or ogives) on the same axes is usually more informative.

What are the boundaries of the class 1.87-3.43?

What are the boundaries of the class 4-18?

In order to graphically compare two frequency distributions, one should use relative frequency distributions in order to take differing sample sizes into account.

Using the class 23-35, what is the upper class boundary?

Find the class with the least number of data values.

What would be the boundaries on the average age for high school graduates if they were reported to be 18 years old?

Thirty students recorded the colours of their eyes, choosing from the colours brown, blue, green, hazel, and black.This data can be appropriately summarized in a

Find the class with the greatest number of data values.

For the class 10-18, the upper class limit is

What is the midpoint of the classes 13.5-17.3?

What is the lower class limit in the class -7 to 14

For the numbers -5, -2, -7, and 0, which of the following that includes all four is a good class?

Greg wants to construct a frequency distribution for the political affiliation of the employees at Owen's Hardware Store.What type of distribution should he use?