A statisitician wishing to test a hypothesis that students s

A statisitician wishing to test a hypothesis that students score at most 75% on the final exam in an intro stats course decides to randomly select 20 students in the class and have the take the exam early. The average score of the 20 students on the exam was 72% and the standard deviation in the population is known to be 15%. The statistician calculates the test statistic to be -0.8944. If the statistician chose to do a two-sided alternative, the P-value would be calculated by finding the area to the:

a. right of the absolute value of -.8944 and dividing it by two

b. right of -.8944 and doubling it

c. left of -.8944 and doubling it

d. left of -.8944

Solution

b. right of -.8944 and doubling it

Zo =-0.8944
| Zo | =0.8944
Critical Value
The Value of |Z | at LOS 0.02% is 2.33
We got |Zo| =0.8944 & | Z | =2.33
Make Decision
Hence Value of |Zo | < | Z | and Here we Do not Reject Ho
P-Value : Two Tailed ( double the one tail ) - Ha : ( P != -0.8944 ) = 0.3711
Hence Value of P0.02 < 0.3711, Here We Do not Reject Ho