Choosing Xc

X = number right out of 36 if I am guessing: Binomial, n = 36, π = 1/4, mean 9

Xc = 35: α = Pr(X > 35) = (1/4)36 ≈ 2 × 10−22

Xcα = Pr(X > Xc | π = 1/4)

Read down: a higher bar, a smaller α.