What's the error on my solution? Can't get the answer.

380 = Arth+3Ar h = 380 3717 A = zach + 2 Tir 760 - 325 2 13 471 2 1676 2 3 f t + 160 3 r d.C - 8 7up - 760 = 3 - 95 95 = 13 r=3.115A propane tank is to hold a volume of 380 m of propane. The tank will be in the shape of a cylinder with a hemisphere on one end. The machinery cannot manufacture a cylinder with any measure (including the radius) that is any smaller than 2 m. The cost of the surface area for the hemisphere is 83 times that of the cylinder (8:3 ratio respectively). The radius that will minimize the overall cost (to two 2 decimal places) is: O 2.06 m C 2.89 m O 13.14 m C 13.81 m