Question

An oil company is interested in estimating the true proportion of female truck drivers based in five southern states. A statistician hired by the oil company must determine the sample size needed in order to make the estimate accurate to within 2% of the true proportion with 99% confidence. What is the minimum number of truck drivers that the statistician should sample in these southern states in order to achieve the desired accuracy?

Answer 1

Answer: n = 2401

Explanation:

Given;

Confidence level = 2% - 99%

n = ? ( which is the sample size is unknown ).

Solution:

Where;

n = [z/E]^2*pq

Since no known value for ( p ) estimate is given, the "least biased" estimate is p = 1/2

Substituting the given data into the formula.

n = [1.96/0.02]^2(1/2)(1/2)

n = 2401

The minimum number of truck drivers the statistician needs to sample for an accurate result is 2401