Problem Solving
试题详情
题目：
| x | C(x) |
|---|---|
| 0 10 20 30 40 50 | 25,000 24,919 24,846 24,781 24,724 24,675 |
A certain manufacturer uses the function C (x) = 0.04x 2 – 8.5x + 25,000 to calculate the cost, in dollars, of producing x thousand units of its product. The table above gives values of this cost function for values of x between 0 and 50 in increments of 10. For which of the following intervals is the average rate of decrease in cost less than the average rate of decrease in cost for each of the other intervals?
选项:
A、From x = 0 to x = 10
B、From x = 10 to x = 20
C、From x = 20 to x = 30
D、From x = 30 to x = 40
E、From x = 40 to x = 50
答案:
E
