Final answer:
The equation y = a + bx represents the estimated total MOH in terms of a and bx, where y represents the total MOH, a represents the fixed portion, and bx represents the variable portion dependent on the independent variable x.
Step-by-step explanation:
The equation y = a + bx represents a straight line with a slope of b and a y-intercept of a. In terms of Manufacturing Overhead (MOH), y represents the estimated total MOH, a represents the fixed portion of MOH, and bx represents the variable portion of MOH. The variable portion depends on the value of x, which could be any independent variable related to MOH, such as the quantity of products produced.