1. ## Probability Evaluation (Binomial)

These questions are driving me batty.
Pr (X < 3) for X ~ Bi (10, .2)

That's a less than or equals to sign, I wasn't sure how to do it.

Also, if you have time, can you show me how to do

Pr ( 3 < X < 7) for X ~ Bii (15, .6)

Thanks

2. $\sum_{i=0}^{3} \binom{10}{i} (0.2)^i(0.8)^{n-i} = \binom{10}{0} (0.2)^{0}(0.8)^{10} + \binom{10}{1} (0.2)^{1}(0.8)^{9} +$ $\binom{10}{2} (0.2)^{2}(0.8)^{8} + \binom{10}{3} (0.2)^{3}(0.8)^{7}$

3. Oh you're amazing. I have to do this with the statistical tables (no calculators for some strange reason) and I didn't realise that I could break the probability down like that.

Thanks