The average value of a, b, c, d, and e is
(a + b + c + d + e)/5 = 14
Given that the average value of a, b, c, and d is
(a + b + c + d)/12,
we have
14 = (a + b + c + d + e)/5
14 = (a + b + c + d)/5 + e/5
14 = 4/5 • (a + b + c + d)/4 + e/5
14 = 4/5 • 12 + e/5
14 = 48/5 + e/5
14 = (48 + e)/5
70 = 48 + e
e = 22
