Question

the mean of 25 observations is 20 if each observation is subtracted by 3 then find the new mean? No spam​

Answer 1

Answer :-

New mean is 17.

Solution :-

Mean = 20

Number of observations = 25

Now find sum of observations

We know that

Sum of observations = Mean * Number of observations

Sum of observations = 20 * 25

= 500

Each observation is subtracted by 3.

So multiply 3 with 25

3 * 25 = 75

To find the sum of observations when each observation is subtracted by 3 : subtract 75 from sum of observations

Sum of observations when each observation is subtracted by 3 = 500 - 75

= 425

We know that

Mean = Sum of observations/Number of obervations

New mean = 425/25

= 17

Therefore new mean is 17.

Answer 2

Answer:

mean = 20

observation= 25

each subtracted by 3

total subtracted = 25×3 = 75

new mean =( 500 - 75)/25 = 425/25

= 17