Posted by Katherine on Wednesday, April 21, 2010 at 4:50pm.
you take a threequestion multiplechoice test.each question has four choices.you don't know any of the answers. what is the experimental probability that you will guess exactly two out of three correctly
please help me i am confused

math  Reiny, Wednesday, April 21, 2010 at 4:52pm
right = r
wrong = w
so you want
rrw
rwr
wrr
each of the above has a prob of 1/4 x 1/4 x 3/4 = 3/16
so the prob of getting 2 out of 3 correct is 3(3/16) = 9/16

correction  maths  Reiny, Wednesday, April 21, 2010 at 4:54pm
that should have said:
each of the above has a prob of 1/4 x 1/4 x 3/4 = 3/64
so the prob of getting 2 out of 3 correct is 3(3/64) = 9/64
Answer This Question
Related Questions
 math  you take a threequestion multiplechoice test.each question has four ...
 Algebra Probability PLEASE HELP  You have a 5question multiplechoice test. ...
 Probability  You have a 5question multiplechoice test. Each question has four...
 prealgbra  solve by simulating the problem.you have a 5 question multiple ...
 math  You randomly guess the answers to two questions on a multiplechoice test...
 math  You are writing multiple choice test. Each question has 5 choices, only ...
 Statistics  Over time, a student analyzes her ability to guess correctly after ...
 Stat HW for.  1. A student taking a midterm exam in Ancient History comes to ...
 Statistical concept 689599.7  1. A student taking a midterm exam in Ancient ...
 Math  On a multiple choice test you guess he answers to two questions. Each ...
More Related Questions