Year 12s: what will be the first way you research your future options? >>

Random Questions about S1

- Which one is an unbiased estimator for the population variance:
(Sh^2 – [(Sh)^2]/n) / n - 1
[S(x – mean)^2] / n - 1
n / n – 1
1 / n – 1 (Sx^2 – [(Sx)^2] / n)

(where s is the sign for sum of)

- On a graphical calculator, is standard deviation xon or xon^-1

Also, can I check that you do need to learn these for S1 but I seem to have a tendency of learning things that aren’t even on the syllabus

Reply 1

non-centrally acting

alison_141288

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- On a graphical calculator, is standard deviation xon or xon^-1

Also, can I check that you do need to learn these for S1 but I seem to have a tendency of learning things that aren’t even on the syllabus

standard deviation is xon^-1

which exam board are you with?

Reply 2

thats_my_poison

aqa

is sd =xon where you are using an unbiased estimator of the s.d. becuase im sure my teacher said that you sometimes had to use xon

Reply 3

thats_my_poison

hmm...anyone else know?

anyone?

For Edexcel they generally use s.d = xon

Even in questions where this isn't entirely correct (where you should use xon-1), they still accept this. :smile: