Consider a stratified sampling combined with clustering sampling. There are H strata, Na is the number of PSUS in stratum h, Mi is the size of PSU i in stratum h, Mra = EM M is the total number of size in stratum h. Th PSUS are selected with proportional to size without replacement from stratum h. m SSUS are randomly selected (SRS without replacement) within selected PSU i in stratum h. (a) (2pts) What are the sampling weights for SSUs in each stratum wnsy? (b) (3pts) How would you estimate the population total? Please define notations you need and express the estimator.