Marcos and Adelyn are comparing the amount of lunch money they spent this week. They spent $45 together on lunches. Marcos spent d on lunches, and Adelyn spent $4 less than Marcos. How much money did Marcos spend on lunches this week?

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.