Fill in the blanks:
a. An F-curve is ______________skewed.
b. For an F-curve with df = (14, 5), the F-value having area 0.05 to its left equals the ____________of the F-value having area 0.05 to its right for an F-curve with df = (______________,_____________).
c. The observed value of a variable having an F-distribution must be greater than or equal to ______________.