Complete the following:
Q1. 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.
Center Errors 2000 Errors 1996
Washington 102 24
New York ARTCC 71 44
Indianapolis 54 39
Memphis 38 21
Los Angeles 33 19
Jacksonville 30 27
New York TRACON 27 33
Miami 21 15
Northern California 18 30
Oakland 17 20
Chicago TRACON 14 13
Oakland Bay 8 6
Washington Dulles 7 2
Cleveland 74 32
Chicago ARTCC 70 26
Atlanta 40 36
Dallas Forth-Worth 34 23
Denver 33 11
Kansas City 28 20
Albuquerque 25 21
Boston 21 13
Houston 18 7
Minneapolis 15 13
Salt Lake City 12 8
Miami 8 2
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.
Q2. 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?