In a recent year, about two-thirds of U.S. households purchased ground coffee. Consider the annual ground coffee expenditures for households purchasing ground coffee, assuming that these expenditures are approximately distributed as a normal random variables with a mean of $65.16 and a standard deviation of $10.00
a) Find the probability that a household spent less than $35.00
b) Find the probability that ahousehold spent more than $60.00
c) What proportion of the households spent between $40.00 and $50.00?
d) 99% of the households spent less than what amount?