7. 1!. Which of these sets of points could describe a function? 5
{(4.-2), (-1,5), (-2,-4), (4,-5)}
[{(-6,5), (1,7), (-3,-2), (1, -9)}
'{(5.-11), (4,-2), (6,4), (4,-5)}
{(3,-1), (-6, 1), (2-7), (1,-6)}

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.