SOLUTION: Would someone please check my work on this problem to see if I'm doing it right? A study of postoperative pain relief is conducted to determine if drug A has a significanlty

Question 70093This question is from textbook Statistics Principles and Methods
: Would someone please check my work on this problem to see if I'm doing it right?

A study of postoperative pain relief is conducted to determine if drug A has a significanlty longer duration of pain relief than drug B. Observations of teh hours of pain relief are recorded for 55 patients given drug A and 58 patients given drug B. The summary statistics are :
Drug A - Mean 4.64 - St. Dev. 1.25
Drug B - Mean 4.03 - St. Dev. 1.82

a)Formulate Ho and H1.
b)State the test statistic and the rejection region with α = .10

I think I have done this right, but would appreciate someone checking to see if what I'm doing is right. Here is what I have done.
The hypothesis is:
Ho:μ1-μ2=0 vs. H1:μ1-μ2>0
The test statistic is:
Z= X-Y/√S1²/n1+S2²/n2 = 4.64-4.03/√(1.25)²/55+(1.82)²/58 = 0.61/√.0284+.0572 =0.61/√.0855 = 0.61/.2924 =2.09
The rejection region is:
Rej:Z≥zα =Z≥z.10 = Z≥1.28
2.09 ≥ 1.28, so reject Ho.
Thank you.
kathyb

This question is from textbook Statistics Principles and Methods

Answer by stanbon(48568) (Show Source):
You can put this solution on YOUR website!
I checked your work and conclusion using the "2-Sample Z Test" function
on a TI-83. Your work and conclusion are correct. If you need further
help in your study of stat please email me--no cost.
Cheers,
Stan H.