Answer:
a) Z-score = 0.75
b) Z-score = -32.833
Explanation:
Step(i):-
Given that mean of the Population = 33
Given a standard deviation of the Population = 12
Let 'X' be a random variable in a normal distribution
Let 'X' = 42
Step(ii):-
![Z = (x-mean)/(S.D)](https://img.qammunity.org/2022/formulas/mathematics/college/7qz9anvh7nst24encjda35pw7h9k41ccyr.png)
![Z = (42-33)/(12) = 0.75](https://img.qammunity.org/2022/formulas/mathematics/college/hcs7ll12y26a67oa1dteg3xz2hznokbaw8.png)
Step(iii):-
Given that mean of the Population = 89
Given a standard deviation of the Population = 1
Let 'X' be a random variable in a normal distribution
Let 'X⁻ = 82
![Z = (x^(-) -mean)/((S.D)/(√(n) ) )](https://img.qammunity.org/2022/formulas/mathematics/college/kt728t99mpryt5k31yu7tevsy6xoffjeqb.png)
![Z = (82-89)/((1)/(√(22) ) ) = -32.833](https://img.qammunity.org/2022/formulas/mathematics/college/re8z5gfk5jbhoxs7y40vbe120vhytts9je.png)
Z-score = -32.833