Question

The mean weight of 8 numbers is 15 kg. If each number is multiplied by 2, what will be the new mean?

Answer 1

Solution :

Given mean weight of 8 Numbers

( x ) = 15kg

If each Number is multiplied by 2,

then new mean = 2 × x

= 2 × 15kg

= 30 kg

••••

Answer 2

Answer:

New mean will be 30.

Step-by-step explanation:

1st Method for the solution : -

If each number is being multiplied by a particular number, new mean will be the product of original mean and that number.

So,

New mean = 2 x original mean

New mean = 2 x 15

New mean = 30

2nd Method for the solution : -

It is given that the mean of 8 numbers is 15.

Then,

Total numbers = 8

Mean of numbers = 15

Now,

⇒ Mean = ( sum of observations ) / ( number of observations )

= >  15 = ( sum of observations ) / 8

= >  15 x 8 = sum of observations

= >  120 = sum of observations  

Let, numbers are x₁ , x₂ , x₃..... x₈.

So, x₁ + x₂ + x₃ + x₄ ...... x₈ = 120

According to the question, each number is multiplied by 2,

So, new sum = 2x₁ + 2x₂ + 2x₃ + 2x₄ .... 2x₈

New sum = 2( x₁ + x₂ + x₃ + x₄ ..... x₈ )

From above, x₁ + x₂ + x₃ + x₄ ...... x₈ = 120

So, new sum = 2( 120 ) = 240

Therefore,

New mean = 240 / 8

New mean = 30

Therefore, new mean will be 30