Question 846439
1. Assume that the body weight of tilapia, X, is normally distributed.


Null hypothesis: {{{X <= 20}}}
Alternate hypothesis: {{{X > 20}}}


Z score is calculated as: {{{Z = (mu - X)/(S/sqrt(N))}}}


Critical Z-score is {{{Z[Critical] = (22 - 20)/(15/sqrt(50)) = 0.943}}}


To test the truth of null hypothesis: {{{p(X <= 20) = p(Z <= 0.943) = 0.827}}}

Since {{{p(X <= 20) > 0.01}}} at 1% significance level the null hypothesis is not true. Hence, I will not decide to harvest the stock.

2. Try yourself following the previous problem. If you need help then contact me.