Standard Deviation Measures of Spread

Given that the data is symmetric, which pair of measures should be used to represent the data?

• center: median

  spread: standard deviation

• center: mean

  spread: IQR

• center: mean

  spread: standard deviation

• center: median

  spread: IQR

The distribution shown is symmetric and we should use the mean and the standard deviation to describe the center and spread.

• True

• False

According to the picture, what is the standard deviation of the data set?

• 6.3

• 44

• 3.6

• 3.3

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

According to the picture, what is the standard deviation of the sample data?

• 6.3

• 44

• 3.6

• 3.3

The following symbol represents what?

• the sample mean

• the population mean

• the sample standard deviation

• the population standard deviation

• the sample size

Delaware has an area of 2,000 square miles.  Which is true if Delaware is included in the data set?

• The mean increase

• The range decreases

• The interquartile range decreases

• The standard deviation increases

Which statistics measures how spread out the data values are in a data set?

• mean

• mode

• maximum value

• standard deviation

According to the Empirical Rule, what percentage of data values lie within ONE standard deviation of the mean?

• 68%

• 95%

• 99.7%

• 100%

According to the Empirical Rule, what percentage of data values lie within TWO standard deviation of the mean?

• 68%

• 95%

• 99.7%

• 100%