Question

If the mean of 7, 16, 9, 15, 16, a, 12, 8, b, 11 is 12, write a in terms of b.

Answer 1

Mean = `(sumx)/"N"`

= `(7 + 16 + 9 + 15 + 16 + "a" + 12 + 8 + "b" + 11)/(10)`

∴ 12 = `(94 + "a" + "b")/(10)`

⇒ 120 = 94 + a + b
⇒ a = 120 - 94 - b = 26 - b
∴ a = 26 - b.