A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data.
Do you mean where the sale price is less than or equal to 70% of the sticker price?
Select D2:D30 (or however far down as the data go).
I will assume that D2 is the active cell within the selection.
On the Home tab of the ribbon, select Conditional Formatting > New Rule...
Select 'Format only cells that contain'.
Leave the first dropdown set to the default 'Cell Value'.
Select 'less than or equal to' from the second dropdown.
In the box next to it, enter the formula
=70%*C2
Click Format...
Activate the Font tab and specify Bold.
Activate the Fill tab and select yellow.
Click OK, then click OK again.