I just need a little help

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.

The price of a car has been reduced from $19,000 to $11,590. what is the percentage decrease of the price of the car?

Either enter an exact answer in terms of \piπ or use 3.143.14 for \piπ and enter your answer as a decimal.