Tom wants to order tickets online so that he and three of his friends can go to a waterpark. The cost of the tickets is $16.00 per person. There is also a $2.50 one-time service fee for ordering the tickets online. Write an expression in terms of n that represents the cost for ordering n tickets online.

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.