Q: Which formula is used to calculate the class width for a frequency distribution with grouped data?

$$\frac{\text{Largest data value} - \text{Smallest data value}}{\text{Desired number of classes}}$$

Q: How do you calculate the relative frequency for a class in a frequency distribution?

$$\frac{\text{Class Frequency}}{\text{Total Frequency}}$$

Q: How do you find the median of an ordered data set with an even number of values?

Median $$= \frac{\text{Sum of 2 middle values}}{2}$$

Question 1

Which formula is used to calculate the class width for a frequency distribution with grouped data?

Accepted Answer

$$\frac{	ext{Largest data value} - 	ext{Smallest data value}}{	ext{Desired number of classes}}$$

Question 2

Given the following class limits: 9-16, 17-24, 25-32, 33-40, 41-48, what is the class boundary for the lower boundary of the first class?

Accepted Answer

$$8.5$$

Question 3

How do you calculate the relative frequency for a class in a frequency distribution?

Accepted Answer

$$\frac{	ext{Class Frequency}}{	ext{Total Frequency}}$$

Question 4

If you have the frequencies 43, 23, and 51 for three classes, what is the cumulative frequency for the third class?

Accepted Answer

$$43 + 23 + 51 = 117$$

Question 5

What is the formula for finding the mean of a data set?

Accepted Answer

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

Question 6

How do you find the median of an ordered data set with an even number of values?

Accepted Answer

Median $$= \frac{	ext{Sum of 2 middle values}}{2}$$

Question 7

In a stem-and-leaf display, what does the 'stem' represent?

Accepted Answer

The left part of each number, typically the tens digit

Question 8

If a data set has two values that appear the same maximum number of times, what is the mode?

Accepted Answer

The data set is bimodal

Question 9

How do you compute a 5% trimmed mean for a sample of 20 values?

Accepted Answer

Remove the lowest 1 and highest 1 value, then compute the mean of the remaining 18 values

Question 10

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

Accepted Answer

Class boundaries

Question 11

A frequency distribution has the following class limits: 1-8, 9-16, 17-24. What is the class midpoint for the second class?

Accepted Answer

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

Question 12

If the total frequency in a distribution is 66, and the frequency for a class is 14, what is the relative frequency for that class (rounded to two decimal places)?

Accepted Answer

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

Question 13

What is the position of the middle value in a data set with $$n$$ values?

Accepted Answer

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

Question 14

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 15

In a real-world scenario, why might a trimmed mean be preferred over a regular mean?

Accepted Answer

To reduce the effect of outliers on the mean

Question 16

If you are making a stem-and-leaf display for the weights of carry-on luggage, what is the first step?

Accepted Answer

Split each number into two parts: the stem and the leaf

Question 17

When constructing a relative frequency histogram, what does the height of each bar represent?

Accepted Answer

The relative frequency for that class

Question 18

If a data set has no value that appears more than once, what is the mode?

Accepted Answer

There is no mode

Question 19

Which step is necessary when making a frequency table for grouped data?

Accepted Answer

Determine the class limits and count the frequency for each class

Describing Data with Tables, Graphs, and Numerical Measures

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