In the simple linear regression model y 5 b0 1 b1x 1 u, suppose that E1u2 2 0. Letting a0 5 E1u2, show that the model can always be rewritten with the same slope, but a new intercept and error, where the new error has a zero expected value.

Asmall business produces and sells balls. the fixed costs are $20 and each ball costs $4.32 to produce. each ball sells for $8.32. write the equations for the total cost, c, and the revenue, r, then use the graphing method to determine how many balls must be sold to break even.