If 22 mAs and a 5:1 grid results in an excellent radiograph,…

If 22 mAs and a 5:1 grid results in an excellent radiograph, how much mAs is needed with a 12:1 grid?        Grid Ratio:                          CGF/ BF No grid     1 5:1     2 6:1     3 8:1     4   12:1     5   16:1     6