Measures of Spread and Center

When finding the median, if you have two numbers in the middle, you should

• add them together and divide by two

• find the number in between the two

• find the mean of the two numbers

• all of these

If a number is added to the set that is in the middle of the data, how does this affect the range?

• increase

• decrease

• stay the same

• both increase and decrease

Which of the following is a measure of variability?

• mean

• median

• mode

• standard deviation

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

• 8

Given a variance of 64, what is the standard deviation?

• 8

• 4096

• 0

• 6.8

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

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 THREE standard deviation of the mean?

• 68%

• 95%

• 99.7%

• 100%

Jade subtracted the smallest value from the largest value in the data set. What statistic was she calculating?

• standard deviation

• range

• variance

• mean