Assuming the following data for a population of 800 elements distributed into 4 stratum: Stratum Size Variance cost per unit h Nh ($) 1 150 64 0.2 2 230 81 0.1 3 320 25 0.4 4 100 100 0.9 ) If we plan to use a Stratified Random Sample of size 160 to make an estimate of (average). a) Compute: The allocation that will yield an estimate having the lowest variance per unit cost b) Compute the total cost of sampling (C):