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 normally distributed as a normal random variable with a mean of $45.16 and a standard deviation of $10.00.
1. Find the probability that a household spent less than $25.00.
2. Find the probability that a household spent more than $50.00.
3. What proportion of the households spent between $30.00 and $40.00?
4. 99% of households spent less than what amount?