Question

The mean of n observation is X'. If the first observation is increased by 1, the second by 2, the third by 3, and so on, then the new mean is
A. x'+(2n+1)B. x'+n+1/2C. x'+(n+1)D.x'-n+1/2

Answer 1

New mean of the data = x'+ $\frac{n+1}{2}$

Given:

• The mean of n observation is X'.

• First observation is increased by 1, the second by 2, the third by 3, and so on.

To find:

      New mean of the data.

Explanation:

• Mean of the data = $\frac{Addition\ of\ no.\ of \ observation}{No.\ of \ observation}$
• In this type of problem the simple way to solve thus problem is to check option one by one.
• Assume mean of the given observations are 7,  8,  9

                  Mean = X' = $\frac{24}{3}$ = 8

• And new observations are 8,  10,  12

          New mean = $\frac{30}{3}$ = 10

• Now check the options

• Option A : x'+(2n+1) = 8+(2×3+1) = 15

• Option B :  x'+n+1/2 = 8+$\frac{4}{2}$ = 10 .........................satisfies the given condition

To learn more....

1. The mean age of a group of 100 children was 9.35 years the mean age of 25 of them was 8.75 years and that of another 65 of them was 10.51 years whar is the mean age of the remaining children

brainly.in/question/10972224

2. The mean of 25 observation is 65 and mean of next 10 observation is 62 find the mean of all 35 observation.

brainly.in/question/2396151