61.

59. The circumference of a circle is given by C(r) = 2Tr where r is the radius of the circle. What is the circumfer- ence of a circle with a 5-in. radius? 60. The volume of a sphere of radius r is given by V(r) = - TP3 3 Compute V(2.1) and V(2). What does the quantity V ( 2.1) - V(2) measure ? 61. CONSUMPTION FUNCTION The consumption function in a cer- tain economy is given by ermine C(y) = 0.75y + 6 where C(y) is the personal consumption expenditure, y is the disposable personal income, and both C(y) and y are measured in billions of dollars. Find C(0), C(50), and C(100). X 62. FRIED'S RULE Fried's Rule, a method for calculating pedi- atric drug dosages, is based on a child's age. If a denotes t