statistics. Would like some explanation in detail please.

Question

135 145 95 140 135 95 110 50 90 165 110 125 80 125 130 110 25 75 65 100 60 125 115 135 95 90 140 40 75 50 130 85 100 160 135 45 135 115 75 130

The waking times ( in minutes past 5:00 A.M.) of 40 people who start work at 8:00 A.M. are shown above. Assume the population standard deviation is 45 minutes. Find

1. The point estimate of the population mean

2. The margins of error for confidence interval 80%, 90%, 95% and 99%

3. Construct 80% 90% 95% and 99% confidence intervals for the population mean. Which level of confidence produces the widest confidence interval? Explain your reasoning.

4. Determine the minimum sample sizes required to be 90%, 95% and 99% confident that the sample mean waking time is within 10 minutes of the population mean wakin

Answer 1

1. The point estimate is the sample mean.

 

2. What formula have you learned to use to calculate the confidence interval? It might look like: 

 

sample mean ± some formula.  The "some formula" calculation is the margin of error.

 

3. use your formula for confidence interval

 

4. Use the formula from (2) that you used for max error.

 

 

Need more help?  Where are you stuck?