The set {5, 8, 10, 16, 18, 28, 30, x} has eight members. The mean of the set's members is 4.5 less than x. What is the value of x?
( 5 + 8 + 10+ 16 + 18 + 28 + 30 + x ) / 8 = x - 4.5
(115 + x) = 8 ( x - 4.5)
115 + x = 8x - 36
115 + 36 = 8x - x
151 = 7x
151 / 7 = x
