The air temperature is −6℃ at sunrise and rises 4℃ every hour for several hours. The air temperature after x hours after sunrise is represented by the function f(x)=4x-6. Use intercepts to graph the function and interpret the intercepts in context.

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.