Quiz 1: Measures of Center and Variability Quiz

Suppose you have 3 data values of 12, 14, and 16. If a value of 30 is added to the data set, what effect does this have on the mean and standard deviation?

• The mean and standard deviation will not change.

• The mean will increase, but the standard deviation will not change.

• Both the mean and standard deviation will increase.

• The mean will stay the same, but the standard deviation will increase.

If sample A has a standard deviation of 10 and sample B has a standard deviation of 2, which sample has the larger spread of values?

• Sample A

• Sample B

• Neither, standard deviation does not measure spread.

Answer explanation

The smaller the spread, the less spread the observations are on average about the mean.

Whew! This quiz is making my head tired.

The interquartile range for the following set of values is

70, 50, 30, 40, 35, 30, 30, 40, 15

• 15
• 20
• 25
• 30

Answer explanation

The interquartile range is a more resistant measure of spread than the standard deviation. Resistant measures are less susceptible to be influenced by extreme values.

He could not resist the sun today. I'm the IQR of the two of us.

Tags

CCSS.6.SP.B.5C

The heights of some students are given.

158cm 172cm 164cm

164cm 167cm 159cm

What is the range of the heights?

• 13cm

• 14cm

• 164cm

• 330cm

Tags

CCSS.6.SP.B.4

CCSS.HSS.ID.A.1

Standard deviation can be used to compare the 'spread' of two sets of data. If the value of the standard deviation is very small the data is more

• dispersed and therefore spread farther from the mean

• consistent and therefore more closely grouped together

Tags

CCSS.7.SP.B.4

Standard deviation can be used to compare the 'spread' of two sets of data. If the value of the standard deviation is larger, the data is more

• dispersed and therefore spread farther from the mean

• consistent and therefore more closely grouped to the mean

Tags

CCSS.7.SP.B.4

The number of miles that Jenna cycled each week for a 8-week period is shown:

38, 42, 28, 52, 48, 36, 31, 25

What is the median number of miles Jenna cycled?

• 36

• 39

• 37

• 52

Tags

CCSS.6.SP.B.5C

If a number is added to a set that is far away from the mean, the standard deviation will .

• increase
• decrease
• stay the same

Mrs. S's class has an average grade of 87. Later on she realizes she left out one grade of a 65. The new mean will _______, and the new standard deviation will_______.

• increase; increase

• decrease; decrease

• increase; decrease

• decrease; increase

Using the given data, the best measure of center and variation to compare the distributions are the​​ .(Hint: You would use the same ones for both of them).

• median and standard deviation

• mean and standard deviation

• mean and IQR

• median and IQR

Tags

CCSS.6.SP.B.5D

CCSS.HSS.ID.A.2