3. A researcher wishes to select a stratified random sample from a population with 3 strata as follows (with the usual notation): H Sh Ch 300 30 25 2 500 40 49 200 20 36 (a) If the budget is RM5000 and the overheads RM800, find the allocations for each stratum. (b) Estimate the variance of sample mean using the allocation method from part (a). (c) By using proportional allocation, estimate the variance and compare it to the variance from part (b). (d) Determine the total cost from the allocation of part (c). Explain your result