Problem 4 (Problem Scenario taken from A Course in Business Statistics, fourth edition, by Groebner, Shannon, Fry and Smith) Freedom Hospital is in the midst of contract negotiations with its resident physicians. There has been a lot of discussion about the hospital's ability to pay and the way patients are charged. The doctors' negotiator recently mentioned that the geriatric charge system does not make sense and there may be a difference in the way males are charged versus females. To look into this, the hospital has collected a random sample of patient data for 138 patients. The data are in the worksheet named Freedom Hospital. The operations manager wants your team to use this data to develop a 95% confidence interval estimate for the difference in average charges. To complete Question 4 you should follow the steps below in parts a through m. Place your answers for Question 4 in the worksheet named Freedom Hospital.

a. (3 Points) Calculate the best point estimates of the population means using a built-in Excel function. Place your answers in cells G7 and H7.

b. (3 Points) Calculate the sample standard deviations using a built-in Excel function. Place your answers in cell G8 and H8.

c. (2 Points) Calculate the variances in cells G9 and H9 by writing a formula referencing the appropriate cells.

d. (2 Points) Calculate the sample sizes (n values) in cells G10 and H10 using a built-in Excel function.

e. (2 Points) Calculate the difference in sample means in cell H12 referencing the appropriate cells.

f. (4 Points) Assuming the population variances are equal, calculate the value of the pooled sample variance by writing a formula in cell H13 which references the appropriate cells.

g. (2 Points) Calculate the pooled standard deviation in cell H14.

h. (4 Points) Place the indicated values for the confidence level (in decimal form) and in cells G17 and G18. Calculate the appropriate degrees of freedom for your confidence interval by placing a formula referencing appropriate cells in cell G19. Determine your t or z value by placing the appropriate TINV or NORMINV expression in cell G20.

i. (2 Points) Calculate the margin of error in cell G21 by writing a formula that references the appropriate cells