Excel formula to do a calculation if a cell has a value greater than zero

Hello everyone,

I am having issues with a formula which I am hoping someone will be able to help me with.

I have amounts in cells F1:F14 and a figure in D24. What I am trying to do is (in F15) calculate D24 minus F1:F14 divided by 14 **but only if D24 is greater than zero**. If D24 is a minus figure i need F15 to show as zero.

If you could help that would be great.

As before

=IF(D24<0,0,(D24-SUM(F1:F14))/14)