William invested $800 in an account that paid 5% simple interest per year.
part a how much interest did william earn over 3 years?
part b william withdrew all of his money from the account after 3 years . if the bank charged him a 2% fee, how much money did william withdraw?

According to a study conducted in 2015, 18% of shoppers said that they prefer to buy generic instead of name-brand products. suppose that in a recent sample of 1500 shoppers, 315 stated that they prefer to buy generic instead of name-brand products. at a 5% significance level, can you conclude that the proportion of all shoppers who currently prefer to buy generic instead of name-brand products is higher than .18? use both the p-value and the critical-value approaches.