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# Goodness of fit test

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1. Hello,

I'm having trouble with question (b) as to how to find the probability, P(X=x). Any help would be greatly appreciated!

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2. (Original post by nemanuel96)
Hello,

I'm having trouble with question (b) as to how to find the probability, P(X=x). Any help would be greatly appreciated!

Posted from TSR Mobile
You have to use the PDF of an expeonential distribution with mean 7.5.
3. (Original post by SeanFM)
You have to use the PDF of an expeonential distribution with mean 7.5.
Thanks Sean, yes I used that 1/7.5 = 0.1333. However, I'm not entirely sure how to get the probability for all of them which is annoying.

Would I have to use the midpoints and do e(-0.1333*x)?

Thanks again!

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4. (Original post by nemanuel96)
Thanks Sean, yes I used that 1/7.5 = 0.1333. However, I'm not entirely sure how to get the probability for all of them which is annoying.

Would I have to use the midpoints and do e(-0.1333*x)?

Thanks again!

Posted from TSR Mobile
Oops, sorry - I see what you mean now! Perhaps you can use the CDF instead of the PDF?

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