please answer this question fast... it is for 5 points. please answer in brief

Moving to another question will save this response. > Question 21 5 points Save Answer Question B-1: Sampling procedures and sample size (5 points) Q1: What are the similarities and differences between a cluster sample and a stratified sample? Q2: A researcher invokes a pilot sample and finds that respondents from households with less than $50,000 annual income respond very differently than respondents from households with greater than $50,000 annual income, with regard to the key survey questions. In addition, the researcher's preliminary results show greater variance among respondents in the over $50,000 households. Given the preceding, which probability sampling method should the researcher invoke and why? Q3. Mary Marsh, head aerobic instructor at Tuff-it-Out Fitness Centers, wanted to estimate the proportion of all 19-39 year olds who aerobically exercise at least once each week. Mary would like the estimate to be within plus or minus 5% points of the mean and she would like to have 90 percent confidence (z=1.645) in her results. Mary estimates the population proportion at 40%. Calculate the required sample size and show details of your work. For the toolbar, press ALT+F10 (PC) or ALT+FN+F10 (Mac). m I S Paragraph Arial 10pt