A certain quantity is measured on two different scales, the R-scale and the S-scale, that are related linearly. Measurements on the R-scale of 6 and 24 correspond to measurements on the S-scale of 30 and 60, respectively. What measurement on the R-scale corresponds to a measurement of 100 on the S-scale?
20
36
48
60
84
当成直线方程处理。A(6,30),B(24,60),求C(?,100)。
A-B的斜率为k=60-30 / 24-6 = 5 /3
代入y=kx+b, 30=5/3*6+b, b=20.
当y=100, 求?, 则为100= 5/3 x +20, x=48
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