Question

. Hypothesis Test FOR the mean: The test statistic is from your work on the sample mean (1c, i)

Assume the population parameters of DBP are a mean of 84 and a standard deviation of 8 for people NOT on Quinapril. Use the value you calculated for the sample mean of people using Quinapril in part c of #1, to test the claim that people who use Quinapril have lower DBP at the 5% level of significance.

the mean is 79.8

sample size 50

Answer 1

I) Null and alternative hypotheses

Ho : = 84

H1 : < 84 ( claim )

II) test statistic Z = ( xbar - )/(/√n)

Z = ( 79.8 - 84)/(8/√50)

Z test = -3.71

III ) Zcritical for a = 0.05 and left tailed test

Zcritical = Z​​​​​​0.05

Zcritical = -1.645

IV) Decision rule : Reject the null hypothesis Ho if Z < -1.645 , otherwise we fail to reject the null hypothesis

Our Z = -3.71 < -1.645

Conclusion : Reject Ho , There is sufficient evidence to conclude that people who use Quinapril have lower DBP than people who NOT on Quinapril