Question

the grade point average collected from a random sample of 150 students. assume that the population standard deviation is 0.78. find the margin of error if c = 0.98.

Answer 1

Answer:

$E = 14.81\%$

Explanation:

Given

$n = 150$

$\sigma = 0.78$

$c = 0.98$

Required

The margin of error (E)

This is calculated as:

$E = z * \frac{\sigma}{\sqrt{n}}$

When confidence level = 0.98 i.e. 98%

The z score is: 2.326

So, we have:

$E = 2.326 * \frac{0.78}{\sqrt{150}}$

$E = 2.326 * \frac{0.78}{12.247}$

$E = \frac{2.326 *0.78}{12.247}$

$E = \frac{1.81428}{12.247}$

$E = 0.1481$

Express as percentage

$E = 14.81\%$