Standard Deviation and Variance

To find the _________ you add up all the numbers and then divide by how many numbers you have.

• Mean
• Median
• Mode
• Range

The masses of six children are 34.5 kilograms, 42.6 kilograms, 39.8 kilograms, 40.1 kilograms, 53.4 kilograms, and 33.8 kilograms. Find the mean mass.

• 40.7 kg
• 40
• 41
• 50

The number of pages that Carolyn wrote in her journal each day from Monday to Friday is shown below: 
9, 8, 12, 6, 10
What is the mean number of pages she wrote per day?

• 5
• 6
• 9
• 11

The number of miles that Jenna cycled each week for a 7-week period is shown: 
36, 42, 28, 52, 48, 36, 31 
What is the median number of miles Jenna cycled?

• 24
• 36
• 39
• 52

Which of the following is a measure of variability?

• mean
• median
• mode
• standard deviation

All of the below sets have the same mean.
Set 1-Standard Deviation=3.1
Set 2-Standard Deviation=4.9
Set 3-Standard Deviation=1.7
Set 4-Standard Deviation=3.2
Which set of data probably has the points closest to the mean?

• 1
• 2
• 3
• 4

This data is normally distributed.  What percent of the data is in the shaded region?

• 68%
• 95%
• 99.7%
• 50%

Four data sets are shown below.
Set 1: {10, 19, 38, 50, 51}
Set 2: {5, 21, 26, 39, 51}
Set 3: {9, 38, 50, 50, 51}
Set 4: {5, 28, 28, 28, 51}
Which data set has the largest standard deviation?

• Set 1
• Set 2
• Set 3
• Set 4

If the standard deviation of a data set is 4, what is the variance?

• 2
• 16
• 4

Ervin bowled 7 games last weekend. His scores are: 155, 165, 138, 172, 127, 193, 142. What is the sample standard deviation of Ervin's scores?

• 511.33

• 22.61

• 438.48

• 20.94