Due to the Great Recession (2008–2010), new car sales plunged from 16.9 million cars sold in 2005 to 10.4 million cars sold in 2009. This trend resulted in a significant shortage of used cars during the next few years which, in turn, pushed up used car prices. Suppose that the average price of a 5-year-old used car is $16,230 with a standard deviation of $4,740. Assume that the price of a 5-year-old used car follows the normal probability distribution.

a. What is the probability that a randomly selected 5-year-old car costs

1. less than $18,500?

2. more than $11,300?

3. between $10,000 and $14,000?

4. between $12,500 and $17,000?

b. Use Excel to confirm the answers in part a.

c. What is the cost of a 5-year-old car in the 90th percentile?