hi all,

i have a problem with this question....

A summary of 24 observations of x gave the following information:

$\displaystyle \sum(x-a)=-73.2$ and $\displaystyle \sum(x-a)^2=2115$

the mean of these value of x is 8.95

a) find the value of the constant a.

b) find the standard deviation of the value of x.

in this following case, that

$\displaystyle \sum(x-a)=\sum (x)-\sum (a)$ true??

thanks....