This is Neyman allocation so the solution has n1/n = 0.8 x 2 / ( 0.8 x 2 + 0.2 x 4)=2/3. Plug n1=2n/3 and n2=n/3 into the variance formula and solve for n. For part b you must minimize n=n1+n2 subject ...

Heritability is a measure of the proportion of phenotypic variance attributable to genetic variance, and it is an important predictor of the degree to which a population can respond to artificial ...

When you have the average production of three machines, it is easy to calculate the average or mean production. You just add ...