Due to random variations in the operation of an automatic coffee​ machine, not every cup is filled with the same amount of coffee. Assume that the mean amount of coffee dispensed is 8 ounces and the standard deviation is 0.6 ounce. Use the​ 68-95-99.7 rule to complete the following. a. What percent of the cups should have less than 8 ounces of​ coffee? b. What percent of the cups should have less than 7.4 ounces of​ coffee?