This is the formula for the mean, m, of three numbers, x, y and z.
m = x + y + z
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3

a) Work out the value of m, given that x = 2.5, y = 4.5 and z = 6.5.

b) Work out the value of m, given that x = 104, y = 56 and z = 137.

c) Show that the formula can be rearranged as x = 3m - (y+z).

d) Use the formula in part c to find the value of x, given that m = 36, y = 28 and
z = 48.

e) Rearrange the formula to make y the subject.

f) Use your formula from part e to find the value of y, given that m = 3.5, x=6.3
and z = 1.9