A restaurant customer left $1.40 as a tip. The tax was 6% and the tip was 20% of the after tax cost. Which information is not needed to compute the bill after tax and tip? What was the total bill?

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.