According to the Mortgage Banking Association, loans that are 90 days or more past due are considered seriously delinquent (housingwire.com, May 14, 2019). It has been reported that the rate of seriously delinquent loans has an average of 9.1%. 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 rate of seriously delinquent loans is above 8%? 

b. What is the probability that the rate of seriously delinquent loans is between 9.5% and 10.5%?