In-Class Exercise

August 27, 2001

Data were collected on the prices of new cars.The prices shown are in thousands of dollars.The distribution of prices is illustrated by the histogram below.The 5-number summary for this data set is also given below.Use this information to answer the following questions.

 5-Number Summary Max 61.9 Q3 23.3 Median 17.7 Q1 12.2 Min 7.4

a.For this distribution, the mean will be larger than the median.

b.Approximately 10 % of new cars cost between \$20,000 and \$24,000.

c.Fifty-percent of new cars cost less than \$17,000 .

d._75  % of new cars cost more than \$12,200.

e.Are there any outliers in this data set?If so, identify them.

Yes, cars costing around \$60,000 - \$64,000.

f.Why would it be more appropriate to present the median and quartiles to describe the center and spread of this distribution rather than presenting the mean and standard deviation?

This distribution is skewed to the right and contains outliers.  The median and the quartiles are more appropriate for
skewed distributions and are resistant to outliers.