Loans that are 60 days or more past due are considered seriously delinquent. The Mortgage Bankers Association reported that the rate of seriously delinquent loans has an average of 9.1% (The Wall Street Journal, August 26, 2010). Let the rate of seriously delinquent loans follow a normal distribution with a standard deviation of 0.80%
a. What is the probability that the proportion of seriously delinquent loans is above 8%?b. What is the probability that the proportion of seriously delinquent loans is between 9.5% and 10.5%?