A pharmaceutical company wanted to estimate the population mean of monthly sales for their 250 sales people. Forty sales people were randomly selected. Their mean monthly sales was $10,000 with a population standard deviation of $1000. Construct a 95% confidence interval for the population mean.

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Quizplus · Accepted Answer

The correct answer is A because the confidence interval is calculated as:mean +/- z * (standard deviation / square root of sample size)where z is the z-score corresponding to the desired confidence level. For a 95% confidence level, z = 1.96.Plugging in the values, we get:10,000 +/- 1.96 * (1000 / sqrt(40))= 10,000 +/- 1.96 * (1000 / 6.32)= 10,000 +/- 1.96 * 158.33= 10,000 +/- 310.52= [9,690.1, 10,309.9]

A Pharmaceutical Company Wanted to Estimate the Population Mean of Monthly