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# chi squared watch

1. how do you interpret contribution tables for chi squared ocr mei s2?
2. (Original post by esmeralda123)
how do you interpret contribution tables for chi squared ocr mei s2?
I have googled this but found nothing - do you have a link or image?
3. (Original post by Kevin De Bruyne)
I have googled this but found nothing - do you have a link or image?
for example, how would you answer this question, i have looked at the mark scheme but don't understand what tables to use:
question 4 http://mei.org.uk/files/papers/2012_Jan_s2.pdf
mark scheme attached too
4. You don't use the tables you use equations.

To get 9.3180, you do (column total x row total)/ total observed. So (98 x 29)/305

And for 6.3332, its (observed-expected frequences)^2/expected frequency. So (17-9.3180)^2/9.3180

Is this what you were confused about or something else?
5. (Original post by AzureCeleste)
You don't use the tables you use equations.

To get 9.3180, you do (column total x row total)/ total observed. So (98 x 29)/305

And for 6.3332, its (observed-expected frequences)^2/expected frequency. So (17-9.3180)^2/9.3180
i know but the written part of the question is what i don't understand:
Q4iv)
6. (Original post by esmeralda123)
i know but the written part of the question is what i don't understand:
Q4iv)
The larger the value is, the more unexpected the value is.(i.e. it's not the frequency expected). So looking at Woodland finches, there are 10 seen, and approx 10 expected. The overall statistic is 0 as it's what you expect. However with garden thrushes you see 74, however you only expect to see 31ish and as such the contribution to the overall statistic is much greater.
Does that sort of help and make sense?
7. Aw MEI S2 .. cute.

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