Question

Assume that random guesses are made for eight multiple choice questions on an SAT test so that there are n =8 trials ,each with probability of success (correct) given by p=0.2. find the indicated probability for the number of correct answer.
find the probability that the number x or correct answer is fewer than 4​

Answer 1

Step-by-step explanation:

consider k the numbe of correct answers

P(k) = kC8×(0,2)^k×(0,8)^(8-k)

example:

The probability of having 2 correct answers = 2C8×(0,2)^2×(0,8)^(6) = 0.294

the probability that the number x or correct answer is fewer than 4​ =

p(0) + p(1) + p(2) + p(3) = 0.944