calculate the mean and standard deviation of x n=100 Σ(x-20)=125 Σ(x-20)^2=221 I don't really know where to start with this question, any help will be appreciated
calculate the mean and standard deviation of x n=100 Σ(x-20)=125 Σ(x-20)^2=221 I don't really know where to start with this question, any help will be appreciated
Do you know what the notation means? Because if you don't, it would be a good start to look it up.
no, I don't, I'll go search it up I'm not really sure how to calculate mean from this kind of equation?
∑(x−20) means that every single sample point x (all 100 of them) had 20 subtracted from them, and them they were added up. The result is 125.
So if you find the mean of this 'coded' data (i.e. data that had 20 subtracted from each sample point), then you can think about what the mean of the original data must be.
In other words, how does subtracting 20 from each sample point affect the new mean compared to the original one?
∑(x−20) means that every single sample point x (all 100 of them) had 20 subtracted from them, and them they were added up. The result is 125.
So if you find the mean of this 'coded' data (i.e. data that had 20 subtracted from each sample point), then you can think about what the mean of the original data must be.
In other words, how does subtracting 20 from each sample point affect the new mean compared to the original one?