Suppose c and d vary inversely, and d = 2 when c = 17.
a. Write an equation that models the variation.
b. Find d when c = 68.
a. The equation that models the variation is: cd = k, where k is a constant. In this case, when d = 2 and c = 17, we can substitute these values into the equation to solve for k:
2 * 17 = k
34 = k
So the equation that models the variation is dc = 34.
b. To find d when c = 68, we can substitute c = 68 into the equation and solve for d:
68d = 34
d = 34 / 68
d = 0.5
Therefore, when c = 68, d = 0.5.