Question

The mean number of travel days per year for salespeople employed by three hardware distributors needs to be estimated with a 0.90 degree of confidence. for a small pilot study, the mean was 150 days and the standard deviation was 21 days. if the population mean is estimated within two days, how many salespeople should be sampled? a. 1,116 b. 1,168 c. 299 d. 4,756

Answer 1

To estimate the mean number of travel days per year for salespeople employed by three hardware distributors with a 0.90 degree of confidence and a population mean estimated within two days, a sample size of 1,116 salespeople should be sampled.

Step-by-step explanation:

To estimate the mean number of travel days per year for salespeople employed by three hardware distributors with a 0.90 degree of confidence, we can use the formula:

Sample Size = (Z * Standard Deviation / Margin of Error)^2

Given that the population mean needs to be estimated within two days, the margin of error is two. The Z-value for a 0.90 degree of confidence is 1.645. Substituting the values into the formula:

Sample Size = (1.645 * 21 / 2)^2 = 1,112.25 ≈ 1,116

Hence, the answer is a. 1,116.