Wanda's Cafe offers two kinds of espresso: single-shot and double-shot. Yesterday afternoon, the cafe sold 75 espressos in all, 51 of which were single-shot. What percentage of the espressos were single-shot?

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.