Manipal MET2016MathematicsProbability
If X follows a binomial distribution with parameters n=8 and p= 1 2 , then P(|x-4| 2) is equal to
Options
- A119 128
- B116 128
- C29 128
- DNone of these
Correct answer
A. 119 128
Step-by-step solution
We have, aligned & P(|x-4| 2)=P(-2 x-4 2)=P(2 x 6) & =1-[P(x=0)+P(x=1)+P(x=7)+P(x=8)] aligned =1- [ ^8 C₀ ( 1 2 )^8+ ^8 C₁ ( 1 2 )^8 . .+ ^8 C₇ ( 1 2 )^8+ ^8 C₈ ( 1 2 )^8 ]=1- ( 1 2 )^8(1+8+8+1)=1- 18 2^8 = 119 128