Question 59617This question is from textbook elementary statistics
: Multiple-choice questions each have five possible answers(a,b,c,d,e),one of which is correct. Assume that you guess the answers to 3 such problem:
a. Use the multiplication rule to find the probability that the first 2 guesses are wrong and the 3rd is correct.
b. Beginning with 2wrong and 1 correct,(WWC), make a complete list of all possibilities of 2 wrong and 1 correct, then find the probability for each.
c. Based on the preceding results, what is the probability of getting exactly one correct answer when 3 guesses are made?
This question is from textbook elementary statistics
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! Multiple-choice questions each have five possible answers(a,b,c,d,e),one of which is correct. Assume that you guess the answers to 3 such problem:
a. Use the multiplication rule to find the probability that the first 2 guesses are wrong and the 3rd is correct.
P(WWC)=(4/5)^2(1/5)= 0.128
b. Beginning with 2wrong and 1 correct,(WWC), make a complete list of all possibilities of 2 wrong and 1 correct, then find the probability for each.
P(WWC)=0.128, P(WCW)=0.128, P(CWW)=0.128
c. Based on the preceding results, what is the probability of getting exactly one correct answer when 3 guesses are made?
P(2 Wrong and 1 Correct) = 3(0.128)=0.384
Cheers,
Stan H.
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