Friday

December 19, 2014

December 19, 2014

Posted by **Anonymous** on Friday, February 28, 2014 at 7:49pm.

What is the probability that at least 4 of the 20 people are colorblind?

My answer: I got 1-0.984

The answer key says 0.00257394

- Probability -
**Reiny**, Friday, February 28, 2014 at 9:00pmat least 4 means

4 or 5 or 6 or ... or 20 are colourblind

so exclude cases of none, 1 , 2, and 3

colourblind = .05

not colourblind = .95

None:

C(20,0) (.05)^0 (.95)^20 = .358486

one:

C(20,1) (.05) (.95)^19 = .37735..

two:

C(20,2) (.05)^2 (.95)^18 = .1886768

three:

C(20,3)(.05)^3 (.95)^17 = .059582..

adding up those 4 and subtracting from 1 I got .0159

which is the same result as you had

mmmhhhh?

**Answer this Question**

**Related Questions**

Statistics - The distribution of heights of adult males has a mean of 69 inches ...

math - A group of students who are selecting 2 of their group at random to give ...

Math - A group of students who are selecting 2 of their group at random to give ...

statistics - The Better Businesss Bureau reports that they resolve 70% of the ...

Another Data Management Question - Rain is an amazing singer, but cannot play ...

Probability - At a certain university, 30% of the students major in math. Of the...

statistics - 5.20 There are 100 males and 120 females in the graduating class of...

Finite, Math, Probability - Assume that there are 18 board members: 12 females...

Finite, Math, Probability - Assume that there are 18 board members: 12 females...

Data management!! [ Hi economyst] Please Help. - Hi. economyst. Thanks for your ...