Answer:
2.03*[tex]10^{-3}[/tex]
Step-by-step explanation:
Binomial Problem with n = 20 ; p = 1/5
50 % of 20 multiple-choice questions = 10
so P(x=10) = 20C10(1/5)^10*(4/5)^10
= 2.03*[tex]10^{-3}[/tex]
You could also find the probability
that the person answered "at least" 14 questions correctly.
P(10[tex]\leq[/tex]x[tex]\leq[/tex] 20) = 2.03*[tex]10^{-3}[/tex]
