Saturday

September 20, 2014

September 20, 2014

Posted by **Liz** on Tuesday, May 7, 2013 at 5:34pm.

- Statistics -
**MathMate**, Tuesday, May 7, 2013 at 8:38pmUse binomial probability because:

probability is known and does not change over the experiment,

outcome is binomial (success or failure),

each step of the experiment is similar,

p=0.25

n=10

P(r)=number of question correct

=nCr(p^r)(1-p)^(n-r)

nCr = binomial coefficient = n!/((n-r)!r!)

P(0)=0.0563 (zero question correct)

P(1)=0.1877 (1 question correct)

Therefore, to get at least 20%, or 2 or more questions correct, we have

P(2+)=1-(P(0)+P(1))

=0.7560

**Answer this Question**

**Related Questions**

Statistics - On a very short quiz, there is one multiple choice question with 5 ...

Math - Given a multiple choice test with 4 choices for each question and 17 ...

Statistics - Richard has been given a 5-question multiple-choice quiz in his ...

English for john browm - Let me give you something on "multiple-choice" items ...

Probability - Mary took a 20 question multiple-choice exam where there are 4 ...

math - Beth Dahlke is taking a ten question multiple choice test for which each ...

math - Beth Dahlke is taking a ten question multiple choice test for which each ...

statistics - Richard has been given a 5-question multiple-choice quiz in his ...

Math - A multiple choice quiz contains five question. Each question has four ...

math - Part A of your history test has 15 multiple choice questions. Each ...