Question

Question 50 6 pts Surgery Study: Part One: Advocates of minimally invasive surgery (MIS) claim that patients experience more pain with traditional surgery which makes larger incisions than they do with MIS. To investigate this claim, a researcher collected data on patients who underwent cardiovascular surgery, half with traditional surgery and half with MIS. The data consisted of the reported pain level of each patient recorded 24 hours after surgery. The pain scale ranged from 1 to 10, with higher scores indicating more pain. Below are the scores for 15 patients who underwent traditional surgery. Traditional Surgery Data 9 9 8 8 8 8 7/3

I need help please. I can solve this problem

Answer 1

Result:

Descriptive statistics
Traditional
n	15
mean	6.8667
sample standard deviation	1.5976

Let group1 = Traditional and group 2 is MIS

Two sample t test

Ho: µ₁ = µ₂   H₁: µ₁ > µ₂

Upper tail test used$t = \frac{\bar{x_1} - \bar{x_2}}{\sqrt{ \frac{(n_1 - 1) s_1^2 + (n_2 - 1) s_2^2} {(n_1 +n_2 -2)} *{(\frac{1}{n_1} + \frac{1}{n_2})}}}$

$t = \frac{ 6.8667-4.73 }{\sqrt{ \frac{14*1.5976^2+ 14*1.62^2} {(15+15 -2)} *{(\frac{1}{15} + \frac{1}{15})}}}$

Test statistic  t = 3.6372

DF =  n1+n2-2  =28

Table value of t with 28 DF at 0.05 level = 1.7011

Rejection Region: Reject Ho if t >1.7011

Calculated t = 3.6372 falls in the rejection region

The null hypothesis is rejected.

We conclude that traditional surgery patients experience more than MIS patients.

Excel calculations:

Pooled-Variance t Test for the Difference Between Two Means
(assumes equal population variances)
Data
Hypothesized Difference	0
Level of Significance	0.05
Population 1 Sample
Sample Size	15
Sample Mean	6.8667
Sample Standard Deviation	1.5976
Population 2 Sample
Sample Size	15
Sample Mean	4.73
Sample Standard Deviation	1.62
Intermediate Calculations
Population 1 Sample Degrees of Freedom	14
Population 2 Sample Degrees of Freedom	14
Total Degrees of Freedom	28
Pooled Variance	2.5884
Standard Error	0.5875
Difference in Sample Means	2.1367
t Test Statistic	3.6372
Upper-Tail Test
Upper Critical Value	1.7011
p-Value	0.0006
Reject the null hypothesis