Respuesta :
Answer:
probability that exactly 4 out of 9 questions are correct is 0.111
Step-by-step explanation:
Given data:
Test consist of multiple choice question which as 4 choices
Total number of answer randomly = 9
Probability of having 4 answer correctly is calculated as
p = probability of having particular question is answered in correct way
= 1/4 = 0.25
q = probability of having particular question is answered incorrectly
= 3/4 = 0.75
Binomial expansion is beneficial in various situations at which numerical variables are present that are countable or whole numbers
probability that exactly 4 out of 9 questions are correct
[tex]= ^9C_4 (0.25)^4 (0.75)^5[/tex]
[tex]= 120\ times 0.00390 \times 0.2373[/tex]
= 0.111
