In a study, the sample is chosen by writing everyones name on a playing card, shuffling the deck, then choosing the top 20 cards what is the sampling method

Which expression is equivalent to7_/x^2 ÷ 5_/y^3? assume y# 0

An automobile assembly line operation has a scheduled mean completion time, μ, of 12 minutes. the standard deviation of completion times is 1.6 minutes. it is claimed that, under new management, the mean completion time has decreased. to test this claim, a random sample of 33 completion times under new management was taken. the sample had a mean of 11.2 minutes. assume that the population is normally distributed. can we support, at the 0.05 level of significance, the claim that the mean completion time has decreased under new management? assume that the standard deviation of completion times has not changed.

Amachine part consists of a half sphere and a cylinder, as shown in the figure. the total volume of the part is π cubic inches.