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Approximating a Binomial Distribution

For this question I did P(40.5 greater than x greater than 50.5)
I then put it into my calculator in normal CD but then got the answer 0 Screenshot 2020-06-17 at 14.54.11.png

Reply 1

davros

Original post by mathsprobelmssss

For this question I did P(40.5 greater than x greater than 50.5)
I then put it into my calculator in normal CD but then got the answer 0 Screenshot 2020-06-17 at 14.54.11.png

You seem to have the right sort of logic.

Did you calculate the mean and variance of the corresponding Normal distribution correctly from n and p?

Have you tried manually calculating probabilities for >40.5 and >50.5 and subtracting one from the other?

Could it be a calculator issue - which calculator are you using and have you checked the procedure for what you're trying to do?

I'm not a stats expert, but if you post back with a bit more working (and the correct answer if you know what it should be) I'm sure someone will be able to help you :smile:

Reply 2

RDKGames

Study Forum Helper

Original post by mathsprobelmssss

For this question I did P(40.5 greater than x greater than 50.5)
I then put it into my calculator in normal CD but then got the answer 0 Screenshot 2020-06-17 at 14.54.11.png

You have probably mistyped in the calculator so that both limits are the same.