I want solve this probability: For $p= 0.4$ $q=0.8$ $n= 20$
$1-P(5
=
$1-\sum_{k=6}^{10} \binom{20}{k}(0.4)^k(0.6)^{20-k}. Wolfram Alpha -> = 0,2531$
Is calculation method right?
And is there a way to solve this in a hand calculator e.g. CASIO fx-991ES?