A pharmaceutical company wishes to test a new drug with the expectation of **lowering**
cholesterol levels. Ten subjects are randomly selected and pretested. The results are listed
below. The subjects were placed on the drug for a period of 6 months, after which their
cholesterol levels were tested again. The results are listed below. (All units are milligrams per
deciliter.) Test the company's claim that **the drug lowers cholesterol levels**. Assume the
samples are random and dependent, and the populations are normally distributed. Use a =
0.01.
Subject 1 2 3 4 5 6 7 8 9 10
Before 195 225 202 195 175 250 235 268 190 240
After 180 220 210 175 170 250 205 250 190 225
Name of TEST:
Paired T-test
Conditions:
Random and Dependent Samples Normally Distributed
population
Claim:
Claim Ho, Ha
Alpha
Df:
Mean (d) =
Sd =
Test Statistic:
tstat =
P - Value:
Rejection Region Method
t_c= invT (,) = [1pt]
http://www.imathas.com/stattoo
Is/norm.html
Make a decision
Interpretation
Claim
Decision
Claim is
Claim is H.
Reject H
There is enough evidence
There is enough evidence
to reject the claim.
to support the claim.
Fail to reject H
There is not I enough
There is not
enough
evidence to reject the claim evidence to support the claim.