Question

For a particular consumer product, the mean dollar sales per retail outlet last year in a sample of n =10 stores was x =$3,425 with s = $200. The sales amounts per outlet are assumed to be normally distributed. Estimate the standard deviation of dollar sales of this product in all stores last year, using a 90 percent confidence interval.____

Answer 1

To estimate the standard deviation of dollar sales of the product in all stores, construct a confidence interval using the sample mean and standard deviation. The 90% confidence interval is $3,321.74 to $3,528.26.

Step-by-step explanation:

To estimate the standard deviation of dollar sales of the product in all stores last year, we can construct a confidence interval using the sample mean and sample standard deviation. With a 90 percent confidence interval, the critical value is 1.645.

The formula for the confidence interval is: CI = x ± (critical value)*(s/√n)

Plugging in the values, the confidence interval is: $3,425 ± (1.645)*($200/√10) = $3,425 ± $103.26

So, the 90 percent confidence interval for the standard deviation of dollar sales is approximately $3,321.74 to $3,528.26.