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Statistics 't'-distribution question! Watch

1. It's for part b) of this question which I'm having problems with.

Summary Data from a)

mean = 73.266
standard deviation = 4.1525

I'm not really sure how to solve for n, is it a case of trial and error with the values you get from table of 't'-distribution for when q = 0.95 and v = n - 1, or is there a much simpler way to find n?

I end up with:-

t(n-1;0.95) < 0.4816(sqrt(n)) (the answer is n=19)

Thanks for any help!
2. Also I'm slightly stuck with c) and not sure how you form the CI for the variance.
3. If you don't mind me asking, what board is this?

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4. (Original post by Black_Materia_)

It's for part b) of this question which I'm having problems with.

Summary Data from a)

mean = 73.266
standard deviation = 4.1525

I'm not really sure how to solve for n, is it a case of trial and error with the values you get from table of 't'-distribution for when q = 0.95 and v = n - 1, or is there a much simpler way to find n?

I end up with:-

t(n-1;0.95) < 0.4816(sqrt(n)) (the answer is n=19)

Thanks for any help!
Are you sure it's 19. I get 21?
5. (Original post by That_Clever_Guy)
If you don't mind me asking, what board is this?

Posted from TSR Mobile
It is part of a Uni seminar sheet but I do remember questions like this when I did OCR Maths S3, so that's why I listed it under "Sixth Form"

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