Question

A survey asks a random sample of 2500 adults in California if they support an increase in the state sales tax from 7.50% to 7.75%, with the additional revenue going to education. Let Y denote the number in the sample that say they support the increase. Suppose that 30% of all adults in California support the increase. The mean of Y is:_______

Answer 1

`E(Y) = 750`

Explanation:

Given

Sample Size = 2500

Percentage = 30%

Required

Calculate Mean of Y

Mean or Expected Value is calculated as thus;

`E(Y) = np`

Where E(Y) represents the mean

n represents the sample size (or population)

p represents the success probability

`n = 2500 ; p = 30%`%

`p = (30)/(100) = 0.3`

So,

`E(Y) = 2500 * 0.3`

`E(Y) = 750`

Hence, the mean value of Y is 750