Frequency Distributions and Their Graphs

What is the difference between a frequency polygon and an ogive?

• A frequency polygon displays class frequencies while an ogive displays cumulative frequencies

• A frequency polygon is a line graph while an ogive is a histogram

• It is easier to find patterns in the data from a frequency polygon than an ogive.

• There is no difference between a frequency polygon and an ogive.

Use the frequency histogram to answer each question.

Estimate the frequency of the class with the least frequency.

• 32

• 82

• 22

• 72

Estimate the frequency of the class with the greatest frequency.

• 42

• 22

• 72

• 52

Use the ogive to approximate the number in the sample.

• 50

• 275

• 300

• 35

Use the ogive to approximate the correct location of the greatest increase in frequency.

• 22.5-23.5 pounds

• 32.5-33.5 pounds

• 26.5-27.5 pounds

• 19.5-20.5 pounds

What are the boundaries of the class with the greatest relative frequency?

• 18.5-19.5 minutes

• 20-21 minutes

• 35-40%

• 19-21 minutes

Use the given frequency distribution to find the class width.

• 5

• 4

• 3

• 2

Use the frequency polygon to identify the class with the greatest, and the class with the least frequency. What are the boundaries of the class with the greatest frequency?

• 34 - 37

• 32.5 - 35.5

• 31.5 - 36.5

• 31 - 37

What is the difference between relative frequency and cumulative frequency?

• Relative frequency of a class is the proportion of the data in that class, while cumulative frequency of a class is the number of observations in that class.

• Relative frequency of a class is the percentage of the data that falls in that class, while cumulative frequency of a class is the sum of the frequencies of that class and all previous classes.

• Relative frequency of a class is the number of observations in that class, while cumulative frequency of a class is the sum of all the frequencies.

• There is no difference between the two.

Find the midpoints.

• 25.5, 35.5, 45.5, 55.5, 65.5, 75.5

• 20.5, 30.5, 40.5, 50.5, 60.5, 70.5, 80.5

• 21, 31, 41, 51, 61, 71

• 30, 40, 50, 60, 70, 80