The Los Angeles Times regularly reports the air quality index for various areas of Southern
California. A sample of air quality index values for Pomona provided the following
data: 28, 42, 58, 48, 45, 55, 60, 49, and 50.

a. Compute the range and interquartile range.
b. Compute the sample variance and sample standard deviation.
c. A sample of air quality index readings for Anaheim provided a sample mean of 48.5,
a sample variance of 136, and a sample standard deviation of 11.66. What comparisons
can you make between the air quality in Pomona and that in Anaheim on the basis
of these descriptive statistics?