Kindly answer all parts. I'll rate. Don't take too much of time

A researcher wants to get some indication of the wealth that might be accumulated by students 30 years after they graduate. She has a list of some of the students who graduated 30 years ago with their contact details. From another researcher's report she has data showing the wealth accumulated by students varied between degrees. Because the number of students in the her contact list varies by degree she decided a stratified sample should be done to improve the precision bf the analysis. The five degrees are listed below with the number of students who graduated in 1991 along with the estimated variance of the responses for each strata based on the other researcher's data. Strata Number Population in Strata Variance of Strata Cultural Studies ' 102,749,044 The researcher feels she has time to survey and get responses from 40 graduates from 1991. a) Calculate the sample size for each strata and sample error at 95% condence level if the number sampled for each strata is the same. b} Use proportional allocation to calculate the number to be sampled in each strata. Calculate the sample error at the 95% confidence level. c) Using Wallocation (the cost to sample a unit in any strata is the same] to calculate the number to be sampled in each strata. Calculate the sample error at the 95% confidence level. d} Explain in less than K page why the results for the sample error in a], b] and c} are different. e) Normally the variance of the variable y we are measuring is not known so we cannot stratify using it. Instead, we often use the variance for an auxiliary variable x which is known for all units. If there were several possible auxiliary variables available explain how you would choose which one to use