1. Calculate the sample mean and standard deviation for the time to reach -10°C for the Repair test panels discussed in Example 2.1.4 (p. 12).
2. Calcium levels were measured for three groups of test subjects after taking a vitamin (see Problem 2.1.11, p. 17). The data are recorded in vitamin .txt.
(a) Calculate the sample median and interquartile range for each set of test subjects.
(b) Make side-by-side box plots for the three sets of subjects.
(c) Summarize the differences in calcium levels (if any) between the three sets of subjects.