Of the 30 vehicles for lease on a lot, 18 are SUVs and the rest are full-size sedans. There are 12 black vehicles on the lot, 4 of which are sedans. A salesperson chooses a random vehicle on the lot for a customer to test drive

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.