The Cozine Corporation runs the landfill operation outside Little Rock, Arkansas. Each day, each of the company’s trucks makes several trips from the city to the landfill. On each entry, the truck is weighed. The data file Cozine contains a sample of 200 truck weights. Determine the mean and standard deviation for the garbage truck weights.

Assume that these sample values are representative of the population of all Cozine garbage trucks, and that the weights are normally distributed.

a. Determine the probability that a truck will arrive at the landfill weighing in excess of 46,000 pounds.

b. Compare the probability in part a to the proportion of trucks in the sample that weighed more than 46,000 pounds. What does this imply to you?

c. Suppose the managers are concerned that trucks are returning to the landfill before they are fully loaded.

If they have set a minimum weight of 38,000 pounds before the truck returns to the landfill, what is the probability that a truck will fail to meet the minimum standard?