Question

1. The mean of 10 observations is 15. If one observation 15 is added, then the new mean is __________________.
2. The mean weight of 8 numbers is 15kg. If each number is multiplied by 2. What will be the new mean?
please answer with steps

Answer 1

Answer:

1)

Step-by-step explanation:

Let the numbers are x1,x2,x3....x10

then according to question,

(x1+x2+x3+.....+x10)÷10 = 15

(x1+x2+x3+.....+x10) = 15 ×10 = 150

Now, if 15 is added then the new mean is

(x1+x2+x3+.....+x10+15) ÷ 16

= (150 +15 ) ÷ 16

= 165 ÷ 16

= 10.31

2) Let the weights are x1,x2,x3,...x8.

then according to question,

(x1+x2+x3+.....+x8) ÷ 8 = 15

(x1+x2+x3+.....+x8) = 15×8 = 120

If each weight is multiplied by 2 then the new mean is.

{2 × (x1+x2+x3+......x8)} ÷ 8 = {2× 120}÷8

= 30