In: Statistics and Probability
A researcher did a one-tailed hypothesis test using an alpha level of .01, H0 was rejected.A colleague analyzed the same data but used a two-tailed test with α=.05, H0 was failed to reject. Can both analyses be correct? Explain your answer.
Yes Both analysis can be correct.
Prove it by an example :
Null hypothesis : Ho:
Alternate hypothesis : Ha(Two tailed test)
Given | |
Hypothesized Mean : | 1 |
Sample Mean : | 1.2 |
Population Standard Deviation : | 0.4 |
Sample Size : n | 12 |
Level of significance : | 0.05 |
p-value for two tailed test :
As P-Value i.e. is greater than Level of significance i.e (P-value:0.0834 > 0.05:Level of significance); Fail to Reject Null Hypothesis
For the same data;
The hypothesis is changed to make it into one tailed test.
Null hypothesis : Ho:
Alternate hypothesis : Ha :
p-value for right tailed test :
As P-Value i.e. is less than Level of significance i.e
(P-value:0.0417 < 0.05:Level of significance); Reject Null
Hypothesis