Question 1023341
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Just like converting any other number to a percentage; you move the decimal point two places to the right.  So:


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ 4.096\ \times\ 10^{-9}\ =\ 4.096\ \times\ 10^{-7}%]


If you want to calculate the probability of "more than 2 correct" straight up, then you are right, you have to calculate the probability of exactly 3 plus the probability of exactly 4, plus...and so on all the way up to 12.  However, the probability of MORE THAN 2 is equal to 1 minus the probability of 2 OR LESS.  Calculate the probability of 0, 1, and 2, add the three probabilities, and subtract from 1.


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ P_{12}(\geq 3,0.2)\ =\ \sum_{k\ =\ 3}^{12}{{12}\choose{k}}\left(0.2\right)^k\left(0.8\right)^{12\,-\,k}\ =\ 1\ -\ P_{12}(< 3,0.2)\ =\ 1\ -\ \sum_{k\ =\ 0}^{2}{{12}\choose{k}}\left(0.2\right)^k\left(0.8\right)^{12\,-\,k}]


If you have either Excel (on a Windows machine) or Numbers (on a Mac), open a spreadsheet and enter


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ =BINOMDIST(3,12,0.2,TRUE)]


John
*[tex \LARGE e^{i\pi}\ +\ 1\ =\ 0]
My calculator said it, I believe it, that settles it

*[tex \Large \ \
*[tex \LARGE \ \ \ \ \ \ \ \ \ \  

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