Stat Question Number 13

Question

Multiple-choice questions each have 4 possible answers, one of which is correct. Assume that you guess the answers to 4 such questions.

Use the multiplication rule to find the probability that the first three guesses are wrong and the fourth is correct. That is, find P(WWWC)P(WWWC), where C denotes a correct answer and W denotes a wrong answer.

(round answer to 4 decimal places)

P(WWWC)=P(WWWC)= 

What is the probability of getting exactly one correct answer when 4 guesses are made?

(round answer to 4 decimal places)

P(exactly one correct answer) = 

Answer 1

P(1st 3 wrong, 4th correct) = (3/4)^3(1/4) = 3^3//4)^4 = 27/256 = about 10.5%

= 0,10546875

=about 10.5469%