A park fountain sprayed 20 gallons of water in 1/2 an hour, then was turned off for awhile. When it was turned back on, it sprayed 30 gallons in 3/4 of an hour. Explain how you know that the fountain sprayed water at the same rate both times it was on.

According to a study conducted in 2015, 18% of shoppers said that they prefer to buy generic instead of name-brand products. suppose that in a recent sample of 1500 shoppers, 315 stated that they prefer to buy generic instead of name-brand products. at a 5% significance level, can you conclude that the proportion of all shoppers who currently prefer to buy generic instead of name-brand products is higher than .18? use both the p-value and the critical-value approaches.