How many business students must be randomly selected to estimate the mean monthly earnings of business students at one college?

We want 95% confidence that the sample mean is within $135 of the population mean, and the population standard deviation is known to be $538.

Dylan and dusty plan to take weekly surfing lessons together. if the 2-hour lessons are $20 per person and they plan to spend $100 each on new surfboards, what is the maximum number of lessons the two can take if the total amount spent for lessons and surfboards is at most $480?

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

Rosy waxes 2/3 of her car with 1/4 bottle of car wax.at this rate,what fraction of the bottle of car wax will rosey use to wax her entire car