According to the Kentucky Transportation Cabinet, an average of167,000 vehicles per day crossed the Brent Spence Bridge into Ohioin 2009. Give the state of disrepair the bridge is currently under,a journalist would like to know if the mean traffic count hasincreased over the past five years. Assume the population of alltraffic counts is bimodal with a standard deviation of 15,691vehicles per day.
a. What conjecture would the journalist like to find support for inthis sample of vehicles?
b. A sample of 75 days is taken and the traffic counts arerecorded, completely describe the sampling distribution of thesample mean number of vehicles crossing the Brent Spence Bridge.Type out all supporting work.
c. The sample of 75 days had an average of 172,095.937 vehiclescrossing the bridge. What is the probability of observing a samplemean of 172,095.937 vehicles or larger? Type out all supportingwork.
d. Based on the probability computed in part c, what can beconclusion can be made about the conjecture? Explain.
e. If the number of sampled days was changed to 25, how would theshape, mean, and standard deviation of the sampling distribution ofthe sample mean traffic counts be affected?
