Assuming that s = 18,000 is a reasonable estimate for what sample size would be needed to ensure that we could estimate the true mean salary of all production managers with more than 15 years experience within $4200 if we wish to be 95% confident?

The minimum sample size required is 71.

Step-by-step explanation:

The (1 - α)% confidence interval for population mean is:

The margin of error for this interval is:

It is provided that the population standard deviation σ can be estimated by the sample standard deviation s.

The given information is:

s = 18000,

Margin of error = $4200.

Confidence level = 95%

The z-value for 95% confidence level is,

*Use a z-table for the critical value.

Compute the sample size required as follows:

Thus, the minimum sample size required is 71.

i think c. but don't trust it.

step-by-step explanation:

45

step-by-step explanation:

to find a percentage, add a decimal in front and multiply it by the other number.

.25 times 180= 45