Whats the geometric mean of 4 and 18

What is the radius of a circle with an area of 78.5 cubic inches? use 3.14 for pie

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.

Suppose the equation ||x-a|-b|=2008 has 3 distinct real roots and a not =0. find the value of b.