That gives you the given answer.
I suppose they rounded .
On this link scroll down to normal approximations.
That may help with this.
Hey all you binomial distribution fanatics out there!
My question is:
The following is my attempt:Let x be a binomial random variable and suppose n= 20, p=0.2. Then P(μ-σ ≤ x ≤ μ+σ) is:
However the correct answer is 0.844I know that:
μ = n*p = 20*0.2 = 4
σ = sqrt(npq) = 1.788
So Im looking for the the range of x being between 2.21 and 5.788
But the binomial distribution chart for n = 20 only shows k values for whole numbers, so what I would be looking for is: (k=5)-(k=3), which is 0.804-0.411=0.393
can someone help me solve this?
That gives you the given answer.
I suppose they rounded .
On this link scroll down to normal approximations.
That may help with this.
Thanks so much for helping me with this!
I do have a few questions about what you did (to help further my understanding):
In this part: did you round 2.21 down to 2 and 5.78 up to 6? (just to confirm, this part means the sum of the probabilities when X is between 2 and 6 right?)
or are those numbers totally different? and how would affect the question, since you aren't using it?