Can someone help me please

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.

If y varies directly as x and y is 400 when x is r and y is r when x is 4

Marco wrote the equation below. cos ( -π /2) = cos ( 3π / 2) which statement best describes marcos equation?