Question about Lecture Answer and Problem

Hi, My instructor gave an example in class today about difference between probability and statistics. He used the following example: Suppose we flip a fair coin 10 times. What sis the probability of fetting 9 0r more heads? He said the answer was 11/1024. He never showed us how to compute this and said it was simply the addition of two value to get 11/1024. How do you compute this? Thank you for any advice.

Re: Question about Lecture Answer and Problem

Hey mathplease.

Hint: P(X >= 9) = P(X = 9) + P(X = 10) = (1/2)^10 + 10*(1/2)^10 = 1/1024 + 10/1024 = 11/1024.

Remember that in probability, the aim is to use the probability axioms. When you get used to the axioms (and when they become your intuition) then probability will get a lot easier.