16. The circumference of a circle is its perimeter. The formula for circumference is C= 27r or C = 7d, where r is the circle's radius and d is the circle's diameter. a. In these formulas, what is constant and what is variable? b. What are the independent variables? What are the dependent variables? c. Suppose a test question states the radius of a circle as inch. You decide to calcu- late the circumference using r = 0.67 and 3.14 for 7. What will you get? Round to the nearest hundredth. TT. lovlactin d. Your instructor wants a more precise answer and calculates the circumference with r = and the 77 button on the calculator. What will she get? Round to the nearest hundredth. 570 e. What is the percent error of your calculation? (5)-30- 2p=031 UOT am 191