There is a concern about the speed of automobiles traveling over
a particular highway. For a random sample of seven automobiles,
radar indicated the following speeds, in miles per hour: 79, 73,
68, 77, 86, 71, and 69. Assuming a normal population distribution,
answer the following questions.
What is the mean and standard deviation of the random
sample?
Determine the 95% confidence interval for the mean speed of all
automobiles traveling over this highway.