Question

(C) 40
(U 43
34. The average of 15 numbers is 18. If each number is
multiplied by 9, then the average of the new set of
numbers is
(a) 162
(b) 152
(c) 144
(d) 164​

Answer 1

Answer:

144

Step-by-step explanation:

• mean valu is 18
• if we multiply by 9

Answer 2

Answer:

A) 162

Step-by-step explanation:

Average of 15 numbers is 18.

assume y is number of variables= 15 and x be the numbers used

∴ x₁+x₂...x₁₅ / 15 = 18

∴  x₁+x₂...x₁₅ = 15 × 18 = 270....(1)

Now,

every number is multiplied by 9

∴  (x₁+x₂...x₁₅) × 9 / 15 = new mean

∴  (270) ×9 / 15 = new mean [by (1)]

∴ 2430 / 15 = 162 = new mean