Question

Mean of 50 observations was found to be 80.4 but later on, it was discovered that 96 was misread as 69 at one place. Find correct mean
SUPER URGENT!!!! Up

Answer 1

Given :

Mean of 50 observations = 80.4

Applying the formula of mean -

Mean = $\mathsf{{\dfrac{Sum \ of \ all \ Observations}{Total \ Observations}}}$


Putting values, we get

80.4 = $\mathsf{{\dfrac{Sum}{50}}}$


Sum = 80.4 × 50

Sum of all observations = 4020

Now,

A/q

Incorrect number = 69

Correct number = 96

There is an increase in number, therefore

Difference = 96 – 69 = 27

Now,

Correct sum = 4020 + 27 = 4047

Total observations remain same, i.e. 50

Correct mean = $\mathsf{{\dfrac{Correct \ Sum}{Total \ observations}}}$


Correct mean = ${\dfrac{4047}{50}}$


Correct mean = 80.94