After 7 spelling test Matthew scored 68, 81, 90, 95, 51, 83, and 85. If he wants his average to be 80, what does his next score need to be.
mean = ∑x/n
80 = (68+81+90+95+51+83+85+x)/8
Solve for x.
80 = (68+81+90+95+51+83+85+x)/8
Solve for x.