do you always set up binomial probabilities as p(X<=x)?

alaziziomar_

Do you always set it up like that? ≤

Reply 1

username6465783

It depends on the question, sometimes it's the other way

Reply 2

alaziziomar_

Original post

by astudent6651

It depends on the question, sometimes it's the other way

no cos I swear if its the other way they do 1 - that but with the ≤

Reply 3

username6465783

Ohh, I'm sorry I think I misunderstood your question. Yeah you're right, in the question, sometimes it says to do P(X≤x) or P(X≥x) in the question, which is what I meant by sometimes it's the other way. If it is P(X≤x), just put it into your calculator (on binomial CD, in distribution) as it is. if it is P(X≥x), you put P(X≤x-1) into your calculator (on binomial CD), and then do 1-ans on calculate to get P(X≥x). I think there are some calculators that can do it the other way straight away, but I'm not too sure how to do that since I am unfamiliar with them. Hope that made sense.