Question 1

Given a data set with a largest value of 48 and a smallest value of 1, and you want to create 6 classes, what is the class width? Use the formula $$	ext{Class Width} = \frac{	ext{Largest data value} - 	ext{Smallest data value}}{	ext{Number of classes}}.$$

Accepted Answer

$$\frac{48 - 1}{6} = 7.83$$

Question 2

How do you find the class midpoint for a class with lower class limit 9 and upper class limit 16?

Accepted Answer

$$\frac{9 + 16}{2} = 12.5$$

Question 3

If a class has a frequency of 14 and the total frequency is 66, what is the relative frequency for this class? Use $$	ext{Relative Frequency} = \frac{	ext{Class Frequency}}{	ext{Total Frequency}}.$$

Accepted Answer

$$\frac{14}{66} = 0.21$$

Question 4

What is the cumulative frequency after the third class if the class frequencies are 14, 21, and 11?

Accepted Answer

$$14 + 21 + 11 = 46$$

Question 5

How do you find the upper class boundary for a class with an upper class limit of 16.5?

Accepted Answer

Add 0.5 to the upper class limit: $$16.5 + 0.5 = 17.0$$

Question 6

Which of the following best describes how to construct a stem-and-leaf plot?

Accepted Answer

Split each number into a stem and a leaf, list stems in order, and align leaves to the right of their stems.

Question 7

Given the data set: 10, 12, 14, 16, 18, what is the median?

Accepted Answer

$$	ext{Median} = 14$$

Question 8

If the sum of all data values is 144 and there are 6 data values, what is the mean?

Accepted Answer

$$\frac{144}{6} = 24$$

Question 9

How do you find the position of the median in a data set with $$n$$ values?

Accepted Answer

$$\frac{n + 1}{2}$$

Question 10

A data set has the following values: 2, 3, 3, 4, 5, 5, 5, 6. What is the mode?

Accepted Answer

5

Question 11

If you are asked to compute a 10% trimmed mean for a data set of 20 values, how many values should you remove from each end before calculating the mean?

Accepted Answer

2

Question 12

Which of the following is the correct formula for the mean of a frequency distribution?

Accepted Answer

$$\bar{x} = \frac{\sum f x}{\sum f}$$

Question 13

When constructing a histogram, what is placed on the horizontal axis?

Accepted Answer

Class boundaries

Question 14

If a class has a lower class limit of 17 and an upper class limit of 24, what is the class midpoint?

Accepted Answer

$$\frac{17 + 24}{2} = 20.5$$

Question 15

Which of the following best describes a cumulative frequency?

Accepted Answer

The sum of the frequencies for all classes up to and including the current class.

Question 16

If you have the following frequencies for classes: 10, 15, 20, what is the cumulative frequency for the third class?

Accepted Answer

$$10 + 15 + 20 = 45$$

Question 17

Which of the following is NOT a step in constructing a stem-and-leaf plot?

Accepted Answer

Grouping data into classes and counting frequencies.

Question 18

If a data set has no value that appears more than once, what can you say about its mode?

Accepted Answer

The data set has no mode.

Question 19

A sample of airline carry-on luggage weights is: 30, 27, 22, 19, 47, 36, 31, 29, 21, 40. What is the mean weight?

Accepted Answer

$$\frac{30 + 27 + 22 + 19 + 47 + 36 + 31 + 29 + 21 + 40}{10} = 30.2$$

Describing Data with Tables, Graphs, and Numerical Measures

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