题干：公司在判断成本行为时，成本方程式通常表达为y = a + bx， 下列哪一种成本估计方法不能被用来估计固定和变动成本方程式
A图示法
B简单回归
C高低法
D多元回归
考点：Budgeting Concepts and Forecasting Techniques-Correlation and Regression
关键词：fixed and variable costs
解题思路：ABC都是用来模拟一元一次方程的
D是多元一次方程，不能用公式 y = a + bx。 应该用公式Y=A+B1X1+B2X2+B3X3+.......BNXN
Answer (D) is correct . Regression analysis can be used to find an equation for the linear relationship among variables. However, multiple regression is not used to generate an equation of the type y = a + bx because multiple regression has more than one independent variable. In other words, a multiple regression equation would take the form y = a + b 1x1+ b2x2 + b3x3 + . . . .
Answer (A) is incorrect because The graphic approach can be used to estimate a linear function.
Answer (B) is incorrect because Simple regression, which is based on one independent variable, is the best means of expressing a linear cost function.
Answer (C) is incorrect because The high-low method, although unsophisticated, can often give a good approximation of a linear cost function.
