if you subtract 450$ by 12% you should get 396. Subtracting 396 by 110 you will get 286. Im not sure if you mean the 29 is percent or 29$ so im going to percent and put the 29$. If your going by 29% you subtract 286 - 29% and should get 203.06. But if your talking 29$ then you subtract 286 - 29 and you would get 257.
<span>Standard deviation is the square root of variance. Variance is always a non-negative number, since you can't take the square root of a negative number. So neither can be negative </span>
