Statistics Problems with Outliers

The data set below has an outlier of 42.
2, 5, 12, 15, 19, 4, 6, 11, 16, 18, 12, 12, 42
What effect does removing the outlier have on the distribution of the data?

• The mean will decrease
• The median will decrease
• The mean will increase
• The median will increase

Gabriella’s quiz grades are shown below.
88, 92, 92, 96, 98
Gabriella scored a 20 on her sixth quiz. What effect does this score have?

• The low score causes the median to increase.
• The low score causes the median to decrease.
• The low score causes the mean to increase.
• The low score causes the mean to decrease.

Given the following data set
6, 9, 12, 14, 7, 9, 6, 8, 25, 12, 14
What is the mean of the data set without the outlier(s)?

• 9.2
• 9.7
• 11.1
• 12.4

Jacob recorded the ages of the people at a picnic. The data set is listed below.

12, 12, 14, 15, 16, 20, 24, 28, 32, 35, 36

What effect does the arrival of Jacob’s 72-year old grandfather have on the mean age of people at the picnic?

• It increases by about 4.2.

• It increases by about 6.6.

• It decreases by about 4.2.

• It decreases by about 6.6.

A bowler had the following scores after 5 games:
 196, 205, 197, 280, and 202.
How much does the bowler’s mean score increase if the outlier is considered, compared to if the outlier is not considered?

• 13
• 16
• 19
• 22

The salaries of the employees in a company are listed below:

$28,000 $45,000

$31,000 $42,000

$55,000 $72,000

$88,000 $53,000

If $88,000 was found to be an outlier, which salary would be the new maximum?

• $55,000

• $28,000

• $88,000

• $72,000

How do you find the median of a data set that has two middle numbers?

• You pick the higher middle number

• You pick the lower middle number

• Add the two middle numbers and divide it by 2

• Subtract the two middle numbers and divide by 2

The mean of this data set is 17.8. What would happen to the mean if 40 was added to the data set?

• The mean would not change

• The mean would go up

• The mean would go down

Calculate the MEAN for the data set: 6, 7, 12, 8, 7, 4, 8, 8, 7

• 7

• 7.44

• 8

• 7 and 8

Calculate the MEDIAN for the data set: 6, 7, 12, 8, 7, 4, 8, 8, 7

• 7

• 7.44

• 8

• 7 and 8