 Practice with Outliers Terms of Use    Contact Person: Donna Roberts  Directions: These questions deal with outliers.

1.  Given data set: -3, 5, 10, 12, 14, 18, 24, 26, 49, 60
Which of the following statements is true regarding this data?
Choose:
 The value -3 is the only outlier. The value 60 is the only outlier. No outliers exist. Multiple outliers exist.

2.  The following temperatures were recorded (in Fº) each day for two weeks. 82, 72, 83, 75, 80, 78, 82, 73, 60, 79, 80, 78, 83, 81

(a)
What is the outlier in this data, if one exists?

 Choose: 84 83 60 no outliers

(b)
What is the mean for this set of data?

 Choose: 75 77.6 78.9 79.5

(c)
What is the mean for this set of data, if the outlier is removed?

 Choose: 75 77.6 78.9 79.5

(d)
Which of the box plots gives the best representation of this data set?

Choose:
 Box A Box B Both give the same information. Neither represent this data. (e)
Which term best describes this data?

Choose:
 symmetric skewed right skewed left uniform

3.  The data set shown below has an outlier. Determine the outlier and then answer the questions as to what happens to the median, mean, mode, range and standard deviation when the outlier is removed.
Data: 29, 19, 35, 27, 21, 48, 23, 12, 24, 26, 20, 28, 30, 22, 19, 32, 22

If the outlier is excluded, what happens to:
 Increase Decrease No effect
the median?
the mean?
the mode?
the range?
the standard deviation?

4.  Which measure of central tendency is most affected by outliers?
Choose:
 mean median mode 5.  Carlos recorded his friends' scores while playing the video game "Golden Eye Commander". Most of his friends' scores were between 9 and 12. One score, however, was 28, and Carlos identified it as an outlier. What should Carlos do with the score of 28 when recording this data? Choose:
 Ignore the outlier since it is so far from the average scores. Ignore the outlier because he may have recorded the score incorrectly. Eliminate the outlier and ask that friend to play again to obtain a new score. Keep the outlier as it may help to explain a new strategy for playing the game.

6.  Given the box plot: (a) What is the first quartile, Q1, value?
 Choose: 5 8 14 16

(b)
What is the third, Q3, value?
 Choose: 5 8 14 16

(c)
What is the interquartile range, IQR?
 Choose: 5 8 14 16

(d)
What is the upper outlier fence, Q3 + (1.5 • IQR) ?
 Choose: 16 20 24 28

(e)
True or False: The value 28 is an outlier for this data set.

 Choose: TRUE FALSE 