In: Statistics and Probability
The test statistic of z=1.42 is obtained when testing the claim that p does not = 0.663. a. Identify the hypothesis test as being two-tailed, left-tailed, or right-tailed. b. Find the P-value. c. Using a significance level of alphaequals0.05, should we reject Upper H 0 or should we fail to reject Upper H 0?
Solution:
We are given that:
The test statistic is z = 1.42
Claim:
Part a) Identify the hypothesis test as being two-tailed, left-tailed, or right-tailed
Since claim is not equal to type, this is two tailed test.
Part b) Find the P-value
Since this is two tailed test, P-value is given by:
P-value = 2 X P( Z > z test statistic value)
P-value = 2 X ( 1 - P( Z < z test statistic value) )
P-value = 2 X ( 1 - P( Z < 1.42) )
Look in z table for z = 1.4 and 0.02 and find corresponding area.
P( Z < 1.42) = 0.9222
thus
P-value = 2 X ( 1 - P( Z < 1.42) )
P-value = 2 X ( 1 - 0.9222)
P-value = 2 X 0.0778
P-value = 0.1556
Part c) Using a significance level of , should we reject H0 or should we fail to reject H0.
Decision rule:
Reject H0, if P-value < 0.05 level of significance , otherwise we fail to reject H0.
Since P-value = 0.1556 > 0.05 level of significance , we fail to reject H0.