- UID
- 702812
- 在线时间
- 小时
- 注册时间
- 2011-12-18
- 最后登录
- 1970-1-1
- 主题
- 帖子
- 性别
- 保密
|
C. 48 Since the R-scale and S-scale are related linearly, you'll want to find a linear equation to correlate the two values.
Let value on R-scale = x and value on S-scale = y to give the points (6, 30) and (24, 60).
Since you have two points you can find the slope of the line connecting them. Slope formula: (y2 - y1) / (x2 - x1)
(60 - 30) / (24 - 6) = 30/18 = 5/3
Now that you have the slope you can use the point-slope form of a linear equation: y - y1 = m(x - x1) where m = slope. Plug in either point, doesn't matter, I used (24, 60):
y - 60 = 5/3(x - 24) y = (5/3)x - 40 + 60 y = (5/3)x + 20 <-- your equation
Now that you have the equation, plug in 100 for y since 100 is the S-scale value you want to find:
(5/3)x + 20 = 100 (5/3) x = 80 x = 48
So, the R-scale value is 48, or answer C.
Source: http://askville.amazon.com/quantity-measured-scales-R-scale-S-scale-related-linearly-Details/AnswerViewer.do?requestId=2562719 |
|