Question

The mean weight of 32 math students is 98.3 lb. If the students could all stand on the scale together, what would their total weight be?

Answer 1

`32*98.3`

Explanation:

The Expected total weight is
`E(X+Y+...) =E(X)+E(Y) +...`

in this case they have the same mean which is the expected weight so
`n*mu = 32*98.3`

Answer 2

`32 xx98.3 = 3,145.6 lb`

Explanation:

To work out the mean (what we understand as the 'average') we do the following;

`Mean = (" sum (total) of all the values")/("the number of values")" OR " " M=T/N`

As with other formulae in this form, we have 3 ways in which it can be used.

`M = T/N " "T = MxxN" " N = T/M`

Remember that we may add Totals , we may add Numbers , but we may NOT ADD MEANS!

The mean of 32 students is 98.3 lb What do we know?

There are 32 students.(N) The mean is 98.3 (M) `" " T = MxxN`

`rArr Total = 32 xx98.3 = 3,145.6 lb`