Question 181606: Does lovastatin (a cholesterol-lowering drug) reduce the risk of heart attack? In a Texas study,researchers gave lovastatin to 2,325 people and an inactive substitute to 2,081 people (average age 58). After 5 years, 57 of the lovastatin group had suffered a heart attack, compared with 97 for the
inactive pill. (a) State the appropriate hypotheses. (b) Obtain a test statistic and p-value. Interpret the results at α = .01. (c) Is normality assured? (d) Is the difference large enough to be important?
(e) What else would medical researchers need to know before prescribing this drug widely?
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! Does lovastatin (a cholesterol-lowering drug) reduce the risk of heart attack? In a Texas study,researchers gave lovastatin to 2,325 people and an inactive substitute to 2,081 people (average age 58).
After 5 years, 57 of the lovastatin group had suffered a heart attack, compared with 97 for the inactive pill.
-------------------------------------
(a) State the appropriate hypotheses.
Ho: p(placebo)-p(active) =0
Ha: p(placebo)-p(active) >0
--------------------------------
57/2325 = 0.025 97/2081 = 0.047
(b) Obtain a test statistic and p-value.
z(0.047-0.025) = (0.022)/sqrt[(0.047*0.953)/2081 + (0.025*0.975)/2325)]=3.889
---
p-value = P(z>3.889) = 5.043x10^-5
Interpret: There is a 0.00000005043% probability that test results could
have provided stronger evidence for rejecting Ho.
-----------------------------------------------------------
Interpret the results at α = .01.
Since p-value is less than 1% reject Ho.
The lovastatin is a better medicine than the placebo.
-----------------------------------------------------
(c) Is normality assured?
Check whatever normality conditions are required by your text.
------------------------------------------------------
(d) Is the difference large enough to be important?
It is enormous.
-------------------------------
(e) What else would medical researchers need to know before prescribing this drug widely?
I'll leave that to you.
======================================
Cheers,
Stan H.
|
|
|
