Elaine C. answered 03/16/22
Tutor
New to Wyzant
Ph.D. in statistics from the university of Wisconsin Madison
Recall that for variable X which follows Binomial (n,p), the probability:
$P(X=x) = ${n \choose x} \times p^{x} \times (1-p)^{n-x}$
Therefore,
$P(X=4) =\{10 \choose 4 \} \times 0.6^{4} \times (1-0.6)^6 = 0.1114$,
$P(X \leq 4) = P(X=0)+P(X=1)+P(X=2)+P(X=3)+P(X=4) = 0.1662$