You want to buy a new sports car 3 years from now, and you plan to save $4,200 per year, beginning one year from today. you will deposit your savings in an account that pays 5.2% interest. how much will you have just after you make the 3rd deposit, 3 years from now?

Apinhole camera is made out of a light-tight box with a piece of film attached to one side and pinhole on the opposite side. the optimum diameter d(in millimeters) of the pinhole can be modeled by d=1.9[ (5.5 x 10^-4) l) ] ^1/2, where l is the length of the camera box (in millimeters). what is the optimum diameter for a pinhole camera if the camera box has a length of 10 centimeters