S1

The volume of 8 objects give the following results

E(x-200) = 17000 E(x-200)^2 = 86000000

Find the mean
Find the standard deviation
Calculator E(x-300)

for the mean, would you just do 17000+200/8 ?
I have no idea how to do the other two

Did your teacher teach you these formulae? These are what you will have to use
$E(aX+b)=aE(X)+b, Var(aX+b)=a^2Var(X)$
$Var(X)=E(X^2)-(E(X))^2$

the last one yes, i dont know about the others

Okay, so you've got $E(X-200)=17000$ and with the formula I just gave you $E(X-b)=E(X)-b$, so you can now find $E(X)$

would it just be 17200?

Yes

Now for the second part
$Var(X-b)=Var(X)$
$Var(X-200)=E((X-200)^2)-(E(X-200))^2$

so the mean would be 17200/8 = 2150
var(x) = 86000000 - 2150^2 = 81377500?

You shouldn't need to divide it by 8. The mean and E(X) are the same thing.

i dont understand, if the sum of 8 objects = 17200 how come you dont divide by 8 to get the mean?

The question doesn't say that the sum of the 8 objects = 17200, it says that E(X) of the 8 objects = 17200. E(X) = mean, therefore mean = 17200.

The volumes of 8 objects, x , give the following results
E(x-200) = 17000, I used E instead of sigma as I don't know how to type it, does this mean something different?

Yes it does. Rewrite your question saying "sum of" instead of E