What is meant by 95 confidence interval of the mean What sta

What is meant by 95% confidence interval of the mean? What statistic best estimates n? What is margin of error? Find the best point estimate of the population mean. Find the 95% confidence interval of the mean number of jobs. Find the 99% confidence interval of the mean number of jobs. Comparing your answers from 4 and 5, which is smaller? Explain why?

Solution

4)

best point estimate = 7.2

5)

confidence interval = 7.2 +/- 1.96 * 2.1/sqrt(50)

= 7.2 +/- 0.5821

6)

confidence interval = 7.2 +/- 2.576 * 2.1/sqrt(50)

= 7.2 +/- 0.765

7)

hence 4 is smaller since the interval is narrow

8)

margin of error = 10

=>

59.50* 1.96/n = 10

=>

sample size n = 12