Ikeja Electronics Limited applies regression analysis to estimate its total overhead costs. The regression equation derived is $y = 4{,}500{,}000 + 620x$, where $y$ is total monthly overhead cost in Naira and $x$ is machine hours. The coefficient of determination ($R^2$) is 0.91. At 3,500 machine hours, what is the estimated total overhead cost, and what does $R^2 = 0.91$ indicate?
A₦6,670,000; 91% of the variation in overhead cost is explained by machine hoursCORRECT
B₦6,670,000; machine hours cause 91% of overhead costs
C₦2,170,000; 91% of overhead costs are fixed
D₦6,120,000; the regression line passes through 91% of data points