In Exercises, use Table VII to find the required χ2-values. Illustrate your work graphically. Determine the two χ2-values that divide the area under the curve into a middle 0.90 area and two outside...

In Exercises, use Table VII to find the required χ2-values. Illustrate your work graphically.

Determine the two χ2-values that divide the area under the curve into a middle 0.90 area and two outside 0.05 areas for a χ2-curve with

a. df = 11.
b. df = 28.