You are Here: Home >< Maths

# Goodness of fit test watch

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!

Posted from TSR Mobile
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!

Posted from TSR Mobile
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?

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: June 17, 2016
Today on TSR

### Buying condoms for the first time - help!

Discussions on TSR

• Latest
Poll
Useful resources

### Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

### How to use LaTex

Writing equations the easy way

### Study habits of A* students

Top tips from students who have already aced their exams

## Groups associated with this forum:

View associated groups
Discussions on TSR

• Latest

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE