Final answer:
To calculate the total for cells B4, B5, and B6 in cell B8 and the sales tax in cell B9 using the rate in cell Q2, you can use simple formulas and autofill them through the necessary cells.
Step-by-step explanation:
To calculate the total for cells B4, B5, and B6 in cell B8, you can simply use the addition formula. In cell B8, type the formula =B4+B5+B6 and press Enter. Then, to autofill that formula through cell M8, click on cell B8 and drag the fill handle to the right until you reach cell M8.
To calculate the sales tax in cell B9 using the rate in cell Q2, you can use the multiplication formula. In cell B9, type the formula =B8*Q2 and round the answer to the nearest cent using the ROUND function, like this: =ROUND(B8*Q2, 2). Press Enter to get the result. To autofill the formula through cell M9, click on cell B9 and drag the fill handle to the right until you reach cell M9.