Aresearcher evaluates a treatment effect using a two-tailed hypothesis test with a = .05, and the decision is to reject the null hypothesis. if the researcher used the same sample and switched to a one-tailed test that is consistent with the direction found in initial two-tailed hypothesis test, what decision would be made?

if the researcher switches to a one tailed test, the decision will be to definitely reject a= 0.05 and maybe reject a=0.01

Explanation:

in data analysis, the 0.05 means a 95% confidence level and 0.01 means a 1% confidence level. since the decision is to reject the null hypothesis at 95% confidence level and a one-tailed test has the entire 5% on one side, anything  equal to 0.05 and above, the null hypothesis should be totally rejected.

on the other hand, in a two tailed the 5% is split on both sides of the tail.