Write an equation for a function with the given characteristics.
A sine curve with a period of 8π, an amplitude of 3, a left phase shift of π/2, and a vertical translation down 2 units.
f(x) =

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.