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 Blank

What is the difference (in feet) between the shortest and the longest distance of the baseball thrown?

Fill in the Blank

How many baseballs were thrown 5 or more feet?

Multiple Choice

How many students scored more than 80%?

• 10
• 13
• 7
• 15

Fill in the Blank

What is the difference between the highest score and the lowest score on the test?

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 Blank

How many students scored between a 86 and a 90?

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 Blank

What is the missing number in the cumulative frequency column?

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