Question

8)An unprepared student makes random guesses for the ten true-false questions on a quiz. Find the probabilitythat there is at least one correct answer.A)0.100B)0.900C)0.001D)0.999

Answer 1

D.) 0.9990

Explanation:

Given :

Number of questions = 10

True or False questions ; probability of success, p = 1/2 = 0.5

Using binomial distribution :

P(x =x) = nCx * p^x * (1 - p)^(n - x)

Probability of getting atleast one correct answer :

P(x ≥ 1) = p(1) + p(2) +... P(x = 10)

Using a binomial probability calculator :

P(x ≥ 1) = 0.9990