SOLUTION: Statistic question
A psychology professor gives a surprise quiz consisting of 10 true/false questions, and she states that passing requires at least 7 correct responses. Assume
Algebra.Com
Question 764227: Statistic question
A psychology professor gives a surprise quiz consisting of 10 true/false questions, and she states that passing requires at least 7 correct responses. Assume that an unpreprated student adopts the questionable strategy of guessing for each anser.
a. find the probability that the first 7 responses are correct and the last 3 are wrong.
b. is the probability from part a equal to the probability of passing? why or why not?
Please help!!!
Thank you.
Answer by rothauserc(4718) (Show Source): You can put this solution on YOUR website!
If one is guessing, then the probability of getting a correct answer is 1/2 and the probability of getting an answer wrong is also 1/2.
Probability that the first 7 answers are correct is (1/2)^7 = .008
Probability that the last three answers are false is (1/2)^3 = .125
======================================================================
a) sum the two probabilities, .008 + .125 = .133
========================================================================
b) answer is no - because there are multiple ways to get 7 answers correct when guessing:
there are 7 ways to get a passing grade by guessing
7 0 0 3
6 1 1 2
5 2 2 1
4 3 3 0
3 1 4 2
2 2 5 1
1 3 6 0
multiply 7 times .008 = .056
RELATED QUESTIONS
There are 10 true-false questions and 20 multiple choice questions from which to choose a (answered by Theo)
a true false quiz has 10 questions. how many different sets of answers are... (answered by Fombitz)
A biology gives a surprise quiz consisting of 15 multiple choice questions with 5 answer... (answered by edjones)
a teacher gives a 6 question true false quiz. If a students guesses on each question, how (answered by stanbon)
A psychology quiz consists of ten true-or-false questions. If a student knows the... (answered by ewatrrr)
A teacher gives a quick quiz that has 4 true/false questions and 2 multiple choice... (answered by solver91311)
I need assistance with the following statistics:
A literature professor decides to... (answered by robertb)
a teacher gives twelve questions on a quiz. The first two are true/false and the next 10... (answered by stanbon)
a quiz consists of 8 true or false questions. assuming that every question is answered,... (answered by ewatrrr)