A company's management accountant is analysing the reject rates achieved by 100 factory operatives working in identical conditions. Reject rates, Y%, are found to be related to months of experience, X, by this regression equation： Y = 20 - 0.25X. (The correlation coefficient was r = -0.9.) Using the equation, what is the predicted reject rate for an operative with 12 months' experience?
A、17%
B、19%
C、20%
D、23%
A、17%
B、19%
C、20%
D、23%
【参考答案及解析】
Y = 20 - 0.25XX = 12 Y = 20 - 0.25(12) = 17%
Y = 20 - 0.25XX = 12 Y = 20 - 0.25(12) = 17%