The state of Virginia shows than automobile is driven an average23,500 km/year with a stand deviation of 3900 kilometers. Assumethe distribution of measurements is approximately normal.
a) What is the probability that a randomly selected automobileis found to have driven at most 25,000km/yr?
b) What is the probability that a randomly selected automobileis found to have driven between 20,000 and 30,000 km/yr?)
c) Solve for the third quartile.
d) Suppose that the average cost of leasing a car is $300 permonth with a standard deviation of $110. You are interested inleasing a car and decide to investigate the market. You randomlysample 30 people among your acquaintances that are currentlyleasing. What is the probability that among those 30 people thesample mean is less than $260?
e) What is the probability that among the 30 people sampled inpart d) the sample mean is greater than $330?
