What is the probability of the exact sequence HHTH (in that order) .25*.75*.25*.25 .25*.25*.75*.25 .75*.75*.75*.75 .25*.25*.25*.75

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.