The average, or mean, T, of three exam grades, y, v, and w, is given by the
following formula.
y+v+w
T=
3
(a) Solve the formula for w.
(b) Use the formula in part (a) to solve this problem. On your first two exams, your
grades are 85% and 88%: y = 85 and v= 88. What must you get on the third exam
to have an average of 87%?
(a) The formula is w = 3T-y-v.
(b) The answer is%.
4
