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# Mean and Standard deviation help!! watch

1. Σ(x-150)² = 7698
Σ(x-150) = 216

how would you get the first equation to equal Σx² = the answer
and the second one to equal Σx = the answer

thanks
2. (Original post by OmarAl)
Σ(x-150)² = 7698
Σ(x-150) = 216

how would you get the first equation to equal Σx² = the answer
and the second one to equal Σx = the answer

thanks
What are you trying to ask? On its own this has little relevance to SD or means.
3. (Original post by an_atheist)
What are you trying to ask? On its own this has little relevance to SD or means.
so basically the question is calculate the mean and standard deviation of x using the two equations but i dont know how to
4. (Original post by OmarAl)
so basically the question is calculate the mean and standard deviation of x using the two equations but i dont know how to
Do you have a value for n?
5. (Original post by an_atheist)
Do you have a value for n?
yes its 48
6. X bar is equal to the shifted value sum divided by 48, add 150.
SD you just use the normal formula.

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