1. ## Re: please i need help in solving these questions

no i know the binomial distribution.. and i tried to solve it and got this answer 90.15% but its wrong !!!

2. ## Re: please i need help in solving these questions

The number looks close.

BTW why do you know it is wrong? You have the suggested solution?

3. ## Re: please i need help in solving these questions

the right is 92.07 ??????

5. ## Re: please i need help in solving these questions

Yes I have verified that answer 92.07% in R once by normal approximation. Do you know how to do?

6. ## Re: please i need help in solving these questions

opps how did u find this,
i feel that some information missed here

7. ## Re: please i need help in solving these questions

A Binomial(n, p) random variable is distributionally equal to the sum of n independent and identically distributed Bernoulli(p) random variables.

By Central Limit Theorem, if such independent sum minus its mean, and then divided by its standard deviation, then this standardized sum will converge to a standard normal distribution.

Usually the factorials in Binomial pmf is difficult to evaluate when n is large. So this approximation is useful, especially when the computer power is not so great in the past.

8. ## The Following User Says Thank You to BGM For This Useful Post:

help101 (12-11-2011)