Question

It is desired to estimate the average time it takes Statistics students to finish a computer project to within two hours at 90% reliability. It is estimated that the standard deviation of the times is 14 hours. How large a sample should be taken to get the desired interval?

Answer 1

To estimate the average time it takes Statistics students to finish a computer project within two hours at 90% reliability, the sample size needed is approximately 60.

Step-by-step explanation:

To estimate the average time it takes Statistics students to finish a computer project within two hours at 90% reliability, we need to determine the sample size. We can use the formula:

n = ((Z * σ) / E)²

Where:

Substituting the given values into the formula, we get:

n = ((1.645 * 14) / 2)²

Simplifying, we find that a sample size of approximately 60 is required to obtain the desired interval.