Describing Quantitative Data

1.3 Describing Quantitative Data

Frequency, Relative Frequency, Dotplots, Stemplots, Histograms

Graphical Representations of Data

• A dot plot consists of a number line and dots (or points) positioned above the number line.

• Stem plots split each data value into a "leaf" (usually the last digit) and a "stem" (the other digits).

• Histograms use vertical columns to show frequencies.

Fill in the Blanks

Fill in the Blanks

Multiple Choice

How many students scored more than 80%?

• 10
• 13
• 7
• 15

Fill in the Blanks

Multiple Choice

How many students spent 7 hours doing homework that week?

• 1

• 3

• 5

• 6

Multiple Choice

How many students are between 60 and 63 inches tall?

• 3
• 0
• 12
• 7

Multiple Select

Which choices best describe the shape of the data? (Check all that apply.)

• unimodal

• bimodal

• Left Skewed

• Right Skewed

• Symmetric

Fill in the Blanks

Multiple Choice

Which interval shows the greatest number of pets?

• 15-19
• 0-4
• 5-9
• 10-14

Frequency and Relative Frequency

• A frequency is the number of times a value of the data occurs.

• A relative frequency is the ratio of the frequency to the total number of outcomes.

• Cumulative relative frequency is the sum of the current previous relative frequencies.

Multiple Choice

A clumsy teacher spilled coffee over this table of his students' test results. How many students scored below 18?

• 4

• 23

• 18

• 19

Multiple Choice

A clumsy teacher spilled coffee over this table of his students' test results. How many students scored exactly 17?

• 4

• 8

• 2

• cannot be determined

Multiple Choice

What is the missing number?

• 4

• 5

• 20

• 36

Fill in the Blanks

Multiple Choice

How many scores were 26 or below?

• 10

• 20

• 5

• 25

Multiple Choice

What is the relative frequency of students speaking Spanish?

• 16%
• 12%
• 24%
• 48%

Multiple Choice

What is the relative frequency of students speaking Arabic?

• 32%
• 24%
• 10%
• 2%

Multiple Choice

The table above shows a cumulative frequency distribution of runners' ages. According to the table, how many runners are in their forties?

• 25

• 7

• 6

• 10