Atruck drove at an average rate of 45 miles per hour on the highway and 20 miles per hour once it entered the city. if it took the trip, which was 100 miles, in 3 hours, how much of it was in the city?

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.