Suppose it is desired to estimate the average time a customer spends in Dollar Tree to within 5 minutes at 99% reliability. It is estimated that the standard deviation of the times is 15 minutes. How large a sample should be taken to get the desired interval?

Pelle's sister is three years older than pelle the father is 5 times as old as pelle the mother was 28 when the sister was born altogether they are 98 years old how old is pelle?

The probability that a student graduating from suburban state university has student loans to pay off after graduation is .60. if two students are randomly selected from this university, what is the probability that neither of them has student loans to pay off after graduation?

Worth 30 points! in this diagram, both polygons are regular. what is the value, in degrees, of the sum of the measures of angles abc and abd?