Question

If the algebraic sum of deviations of 20 observations measured from 23 is 70

Answer 1

Mean = (sum of observation) / (number of observation)
Sum of observation is given as = 70
Number of observation = 20
∴ Mean = 70/20 = 3.5
But, here observation starts from= 23.
∴ Mean = 23 + 3.5 = 26.5

Answer 2

The new mean = 26.5

Step-by-step explanation:

The complete question:

If the algebraic sum of deviations of 20 observations measured from 23 is 70, mean of these observations would be

Given,

The sum of all observation = 70 and

Number of observation = 20

To find, the new mean = ?

We know that,

Mean $=\dfrac{sum of observation}{Total number of observation}$

$=\dfrac{70}{20}=\dfrac{7}{2}=3.5$

given, the observation starts from = 23

∴ New mean = 23 + 3.5 = 26.5

Hence, the new mean = 26.5