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.