An air traffic control error is said to occur when planes come too close to one another. The following data represent the number of air traffic control errors for a random sample of regions around the US for fiscal years 1996 and 2000.

a. Compute the sample mean number of errors in 1996 and 2000
b. Compute the median number of errors in 1996 and 2000.
c. Given the results of a. and b., decide whether the distrubution of "number of errors in 1996"
is symmetric, skewed right, or skewed left. What about number of errors in 2000?
d. Compute the sample standard deviation number of errors in 1996 and 2000. Which year is
more dispersed?
e. Compute the five number summary for each year.
f. On the same graph, draw boxplots for the two years. Add some general remarks comparing each year's errors.
g. Describe the shape of the distribution of each year, as shown in the boxplots. Does this confirm the result obtained in part c?
h. Determine whether the data for each year contain outliers.
i. Explain why comparing 1996 data to 2000 data maybe misleading.

18. Weights of males vs. females: According to the National Center for Health Statistics, the mean weight of a 20-29 female is 141.7 pounds,
with a standard deviation of 27.2 pounds. The mean weight of a 20-29 Male is 172.1 pounds, with a standard deviation of 36.5 pounds. Who is relatively
heavier: a 20-29 female who weighs 150 pounds or a 20-29 year old male who weighs 185 pounds? Why?

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