Question 905817
Am referring You to stattrek.com (f Dist)
Excellent Resource, also has Calculator for you to check Your work
Re TY
Good to see You are familiar with stattrek.com
Using stattrek calculator...
P(0.85 < F < 1.46) = P(F < 1.46) - P(F <.85)= .82-.36 = .46 
Using TI Function: 
Fcdf (lower boundary, upper boundary, df of numerator, df of denominator) 
P(0.85 < F < 1.46) = Fcdf(.85, 1.46, 20, 26)
........
P(F > c) = 1 - P(F < c) = .1
which says:
P(F < c ) = .9 , c = 1.53