A researcher administers a treatment to a sample of n25 part

A researcher administers a treatment to a sample of n=25 participants and uses a hypothesis test to evaluate the effect of the treatment. The hypothesis test produces a z-score of z=2.77. Assuming that the researcher is using a two-tailed test,

A. The researcher rejects the null hypothesis with a=.05 but not with a=.01

B. The researcher should reject the null hypothesis with either a=.05 or a=.01

C. The researcher should fail to reject null with either a=.05 or a=.01

D. Cannot answer without additional information

Solution

AT 0.05
Critical Value
The Value of |Z | at LOS 0.05% is 1.96
We got |Zo| =2.77 & | Z | =1.96
Make Decision
Hence Value of | Zo | > | Z | and Here we Reject Ho

AT 0.01
Critical Value
The Value of |Z | at LOS 0.01% is 2.56
We got |Zo| =2.77 & | Z | =2.56
Make Decision
Hence Value of | Zo | > | Z | and Here we Reject Ho

B. The researcher should reject the null hypothesis with either a=.05 or a=.01