Say I want to calculate:
\(\sum _{n=0}^2\frac{5!}{n!\left(5-n\right)!}\left(0.3\right)^n\left(1-0.3\right)^{5-n}\)
Anyone know a calculator that will do this?
+118658 I've been mucking around with this for ages and I finally worked out how to do in in Wolfram Alpha.
https://www.wolframalpha.com/input/?i=sum+(5!%2F(n!*(5-n)!)*0.3%5En*0.7%5E(5-n)),++n%3D0+to+2
I am sure there is a probability calc that will work it out a lot easier though.....
Here is the first one that I found but I am sure that there are plent of others about.
http://www.vassarstats.net/textbook/ch5apx.html
See, it is the probability of 2 or fewer than 2 that you want.
The two calculators give the same answer 
