Enter a formula in cell c4 that divides the value in cell b4 by the value in cell b12, using an absolute cell reference to cell b12.

The formula is: "=B4/$B$12"

Explanation:
Follow the following steps:

Step-1:
Select the cell C4.

Step-2:
In the "fx" bar at the top, write the following formula:
"=B4/$B$12"

Make sure to add "equal" symbol before B4/$B$12; furthermore, the absolute reference of a cell can be used by using the "$" (dollar) symbol before the cell number. As, in this case, the cell B12 can be represented in terms of absolute reference as $B$12. As you can see that there is a "$" symbol before "12".