A researcher expects a treatment to produce an increase in the population mean.The treatment is evaluated using a one tailed hypothesis test,and the test produces z = +1.85.Based on this result,what is the correct statistical decision? A)The researcher should reject the null hypothesis with α = .05 but not with α = .01. B)The researcher should reject the null hypothesis with either α = .05 or α = .01. C)The researcher should fail to reject H₀ with either α = .05 or α = .01. D)The researcher should change α.

Question

Quizplus · Accepted Answer

A z-score of +1.85 corresponds to a p-value of approximately .033, which means that the treatment produced a significant increase in the population mean at the .05 level of significance (one-tailed). However, the result is not significant at the .01 level of significance, as the critical value for a one-tailed test at this level is +/- 2.33. Therefore, the null hypothesis should be rejected with α = .05 but not with α = .01.

A Researcher Expects a Treatment to Produce an Increase in the Population