The quantity demanded x for a product is inversely proportional to the cube of the price p for p > 1. when the price is $10 per unit, the quantity demanded is 64 units. the initial cost is $150 and the cost per unit is $2. what price will yield a maximum profit?

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.