As a valet at the mall, davis works 7-hour shifts. he earns $6 per hour and keeps 90% of his tip money. how much does davis need to be tipped so that he takes home exactly $87.50, before taxes are deducted, per shift?

In a survey of 1015 adults, a polling agency asked, "when you retire, do you think you will have enough money to live comfortably or not. of the 1015 surveyed, 534 stated that they were worried about having enough money to live comfortably in retirement. construct a 90% confidence interval for the proportion of adults who are worried about having enough money to live comfortably in retirement.