Please using excel

21) A population consists of the following amounts: 9, 10, 10, 10, 12, 13,

a. Indicate total number possible samples of size 3

b. Compute the sampling distribution of sample means

c. Compare the population mean with the mean of the sampling distribution of sample means

d. Compare the dispersion in the population with that of the sample means.

22) A sample of 40 employees at the company showed that 27 graduated with a degree in management.

a. Construct the 97 percent confidence interval for the proportion of employees who graded with a management degree

b. Interpret the confidence interval

23) Determine the appropriate sample size for the given situations:

a. We want to estimate the population mean within 2, with a 92 percent level of confidence. The population standard deviation is estimated to be 12.

b. The estimate of the population proportion is to be within .12, with a 98 percent level of confidence.

c. Sugar is packaged in 12.5 ounce bags. To test the weight of the bags, a few were checked. The mean weight was 15.943 ounces; the standard deviation, 5.25 ounces. At a 96 percent confidence level, the estimate must not differ by more than .25 ounces.

24)A manufacturer wants to decrease the lead-time of cake box mixes. Past records indicate that the average lead-time of the mix is 215 days. After a revised operational process has been developed, a sample of twelve boxes of cake mix had a mean of 212.333 and a standard deviation of 1.2019.

a. Using a 0.1 significance level, decide if the sample data support the claim that lead-time has been reduced (decreased) using a hypothesis test, five-steps

25)The waiting time at a new hospital follows a normal distribution with a mean of 130 minutes and a standard deviation of 35 minutes. The administrative department selected 15 patients that had an average waiting time of 150 minutes. At the 0.01 significance level, decide if the sample data support the claim that the mean waiting time is greater than 130 minutes.

a) Run a hypothesis test, indicating all the five steps.