In Exercise 3.54 on page 101, we discussed outliers, or observations that fall well outside the overall pattern of the data. The following table contains two data sets. Data Set II was obtained by removing the outliers from Data Set I.

a. Compute the sample standard deviation of each of the two data sets.
b. Compute the range of each of the two data sets.
c. What effect do outliers have on variation? Explain your answer.
Grouped-Data Formulas. When data are grouped in a frequency distribution, we use the following formulas to obtain the sample mean and sample standard deviation.

In general, these formulas yield only approximations to the actual sample mean and sample standard deviation. We ask you to apply the grouped-data formulas in Exercises 3.94 and 3.95.

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Data Set I Data Set II 0 12 14 15 23 10 14 15 17 0 14 15 16 24 12 14 15 10 14 15 17 14 15 16 Grouped-Data Formulas 1n where x, denotes either class mark or midpoin, fi de- notes class frequency, and n ( Σ,D denotes sample size. The sample standard deviation can also be ob- tained by using the computing formula