According to the 2001 Canadian census, university- educated Canadians earned a mean income of $61,823. The standard deviation is $17,301. If incomes are normally distributed, what is the probability that a randomly selected university-educated Canadian earns more than $70,000?

The census referred to in the previous exercise also reported that college-educated Canadians earn on average $41,825. Suppose that incomes are normally distributed with a standard deviation of $13,444. Find the probability that a randomly selected college-educated Canadian earns less than $45,000.

The lifetimes of televisions produced by the Hishobi Company are normally distributed with a mean of 75 months and a standard deviation of 8 months. If the manufacturer wants to have to replace only 1% of its televisions, what should its warranty be?

According to theStatistical Abstract of the United States, 2012(Table 721), the mean family net worth of families whose head is between 35 and 44 years old is approximately $325,600. If family net worth is normally distributed with a standard deviation of $100,000, find the probability that a randomly selected family whose head is between 35 and 44 years old has a net worth greater than $500,000.

A retailer of computing products sells a variety of computer-related products. One of his most popular products is an HP laser printer. The average weekly demand is 200. Lead time for a new order from the manufacturer to arrive is 1 week. If the demand for printers were constant, the retailer would reorder when there were exactly 200 printers in inventory. However, the demand is a random variable. An analysis of previous weeks reveals that the weekly demand standard deviation is 30. The retailer knows that if a customer wants to buy an HP laser printer but he has none available, he will lose that sale plus possibly additional sales. He wants the probability of running short in any week to be no more than 6%. How many HP laser printers should he have in stock when he reorders from the manufacturer?