SOLUTION: Interpret a 99% confidence interval of (5.355, 5.445) for a population mean. A nursing school wants to estimate the true mean annual income of its alumni. It randomly samples 2

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Question 621464: Interpret a 99% confidence interval of (5.355, 5.445) for a population mean.
A nursing school wants to estimate the true mean annual income of its alumni. It randomly samples 200 of its alumni. The mean annual income was $55,200 with a standard deviation of $1,500. Find a 95% confidence interval for the true mean annual income of the nursing school alumni. Write a statement about the confidence level and the interval you find.
An auditor wants to estimate what proportion of a bank's commercial loan files are incomplete. The auditor randomly samples 80 files and finds 12 are incomplete. Using a 95% confidence interval, estimate the true proportion of incomplete files for ALL the bank's commercial loans. Write a statement about the confidence level and the interval you find.
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
 

Hi,

  5.355< mu < 5.445    ||Note:(.445-.355)/2 = .045= ME

  5.4 -.045< mu < 5.4 + .045 

re: n = 200, m = 55200 and SD = 1500 

Find a 95% confidence interval for the true mean annual income of the nursing school alumni.

  ME = 1.96(1500/sqrt(200))}}} = $207.89

55200 - ME < mu < 55200 + ME