Answer:
Probability of getting at least 9 out of 18 correctly is 0.0043
Step-by-step explanation:
We have
n = 18
p = 1/5 for correct answer
q = 4/5 for wrong answer
P( 9 [tex]\leq[/tex] X [tex]\leq[/tex] 18) = 1 - P(0 [tex]\leq[/tex] X[tex]\leq[/tex] 8)
= 1 - 0.9957
=0.0043