Liquid products were first obtained from coal in England during the 1700s. Lamp oil was produced from coal in the United States as early as 1850,...

a) Construct a double stem-and-leaf diagram for these data.

b) Find the sample mean, sample median, and sample standard deviation for these data.

c) Note that the starred observation in the data set is very different from the others. It is potential outlier. Construct a boxplot for these data to verify that the value 10.1 dose, in fact, qualify as an outlier.

d) To see the effect of this outlier, drop it from the data set and calculate the sample mean, median, and standard deviation for the remaining 14 observation. Which measure is least affected by the presence of the outlier? Do you see why it is desirable to report both the mean and median of a data set?