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Class Activity #2

The following data are profits over the past 30 years in a small business (in thousands of dollars):
1518202023242424
2525252627293032
17192021232424
25252627283031

  1. Use the TI-83 to find the range.
  2. Use the TI-83 to determine the mean and standard deviation.
  3. Use the TI-83 to determine the five-number summary of the data. What do these numbers mean?
  4. Use the TI-83 to help you construct the boxplot.
  5. Are there possible outliers? How do you know?

Adapted from www.mathlab.isot.com/math/Statistics/Statlab3.pdf

 

 

 

 

ANSWERS:

  1. The range is 15 – 32.
  2. The mean is 24.23 and the standard deviation is 4.17.
  3. The five-number summary is 15   21   24.5   27   32. 15 is the minimum observation; 21 is the first quartile (Q1) – the observation below which one-fourth of the observations lie; 24.5 is the median – the observation below which one-half of the observations lie; 21 is the third quartile (Q3) – the observation above which one-fourth of the observations lie; and 32 is the maximum observation.
  4. Here is the boxplot:
  5. There does not seem to be any outliers? There are no observations on the far-left or far-right that are separated from the rest of the distribution.