can anyone help (3)

c) Reed and Chagnon (1987) wanted to estimate the number of greater snow geese on Bylot Island, in Canada's Northwest Territories (the island is an important breeding ground for the bird). They gridded the island into 400 2 x 2 km plots (excluding areas that were patently not usable by geese). They divided the 400 plots into three strata (high, medium, and low quality), based on ecological factors that are known to be associated with goose abundance. Using their estimates of stratum standard deviations (SDs) and sizes, determine the appropriate allocation for a sample of 83 (their actual sample sizes). State the name of this allocation method and any assumption being made. [8] Stratum Stratum Size Mean SD High quality 65 412.5 316.9 Medium quality 127 136.8 127.7 Low quality 208 16.2 30.5