Billy and Tommy plant seeds in a garden. The garden is divided into 100 equal parts. Tommy planted 2/10 of the garden. Billy planted 28/100 of the garden. How much of the garden have Billy and Tommy planted?

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.