Effects of Outliers on Data

The prices at several different stores for a pair of shoes are shown below.
$78, $79, $81, $82, $83
Two days later, another store has the same shoes on sale for $65. How does the new price affect the data?

• Only the range was affected.
• The median increased, and the range increased.
• The mean increased, and the range increased.
• The mean decreased and the range increased.

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

The table below shows the lengths of fences a company installed during a week. 
Which statement is true?

• The 275-foot fence caused the mean to be significantly lower than the median.
• The 275-foot fence caused the median to be significantly lower than the mean.
• The 2,250-foot fence caused the mean to be significantly greater than the median.
• The 2,250-foot fence caused the median to be significantly greater than the mean.

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.

A value that is much higher or much lower than the other values in a set of data.

• Outlier
• Box Plot
• Range
• Histogram

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

If 20 is added to the data set below, which statement will be true?
50, 55, 55, 60, 62

• The median will be 20
• The mode will increase
• The mean will increase
• The mean will decrease

The data below represent the ages of several people in a class.What effect does Mr. Smith’s age have on the data set?

• Mr. Smith’s age increases the mode of the data.
• Mr. Smith’s age decreases the mean of the data.
• Mr. Smith’s age increases the mean of the data.
• Mr. Smith’s age increases the median of the data.

A data set is shown below.
56, 64, 73, 59, 98, 65, 59
If the outlier is removed from the data set, which measure of central tendency will be least affected?

• range
• mode
• median
• mean

A realtor wants to give a customer an idea of housing prices in a neighborhood. All the houses are priced within $20,000 of one another, except one house that is much larger and more expensive than the rest. Which measure(s) of central tendency will be most affected by the one expensive house?

• Mode only
• Mean only
• Both mode and mean
• Both mean and median