Reference no: EM1320366
Q1) Unexpectedly, your phone rings. It's Dr.Schott who wishes you to do the analysis of infection rates at two HHMS subsidiary outpatient surgical facilities. One, Panhandle Surgical Center, is located in small town in West Texas. Another, Piney Woods Surgical Center is located in East Texas, Dr. Schott is concerned about differences in complication rate at two centres. System measures complication rate each month. Following information has been made available for your use:
Surgical Center
|
Sample Size
|
Mean Complication Rate
|
Standard Deviation
|
Piney Woods
|
11 months
|
17.6 (per 100 cases per month)
|
8.8
|
Panhandle
|
16 months
|
6.2 (per 100 cases per month)
|
21.4
|
a) Looking at data, you observe that sample standard deviations are in fact pretty different, in which case pooled variance t-test might not be suitable. Do F-test to determine whether there is a important difference between population variance for Piney Woods Medical Center and the Panhandle Medical Center. Use Type - I error rate of 5% (alpha = 0.05). Illustrate all five parts of test including the conclusion.
b) Pleased with information gained by comparing two surgical centres in prior question, the Medical Director decides to expand analysis to all 6 surgical centers in System. Research staff gathers 6 samples of 16 monthly surgical complication rates for each centre. The ANOVA analysis of null hypothesis that mean complication rate at each of six centres is same yields the following result:
Source
|
DF
|
SS
|
MS
|
F
|
P-value
|
Among
|
5
|
7214
|
|
2.79
|
|
Within
|
60
|
|
517.13
|
|
|
Total
|
65
|
38242
|
|
|
|
1) Compute the missing value for SS (Within)?
2) Determine the missing value for MS (Among)?
3) Assume that p-value was 0.07, would you reject null hypothesis of equal mean rates for a Type- I error rate of 5%? (Circle one)
REJECT
DO NOT REJECT