Identify which type of sampling is used: random, systematic, convenience, stratified, or cluster. to determine customer opinion of their pricing, greyhound lines randomly selects 120 busses during a certain week and surveys all passengers on the busses.

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.