Determine the two F-values that divide the area under the curve into a middle 0.90 area and

Question:

Determine the two F-values that divide the area under the curve into a middle 0.90 area and two outside 0.05 areas for an F-curve with
a. df = (10, 8).
b. df = (12, 12).
Use Table VIII and, if necessary, the reciprocal property of F-curves to find the required F-values. Illustrate your work graphically.