State the null and alternative hypotheses for the situation described below for a statistical test. Testing to see if average sales are higher in stores where customers are approached by salespeople than in stores where they aren't. Let group be the group of stores where customers are approached by salespeople and let group be the group of stores where customers are not approached by salespeople.

The price of an item has been reduced by 30%. the original price was $30. what is the price of the item now ?

The measure of an angle is 117°. what is the measure of a supplementary angle?

Suppose that 3% of all athletes are using the endurance-enhancing hormone epo (you should be able to simply compute the percentage of all athletes that are not using epo). for our purposes, a “positive” test result is one that indicates presence of epo in an athlete’s bloodstream. the probability of a positive result, given the presence of epo is .99. the probability of a negative result, when epo is not present, is .90. what is the probability that a randomly selected athlete tests positive for epo? 0.0297