Question

Mean of 30 observations was found to be 80.5 but later on it was discovered that 97 was misread as 79 at one place. Find the correct mean

Answer 1

Answer:81.1

Step-by-step explanation:

Given,

Mean of 30 observations= 80.5

Sum of 30 observations = 80.5*30=2415

Sum of correct 29 observations= 2415-79= 2336

Correct sum of 30 observations= 2336+97= 2433

So, correct mean of 30 observations= 2433/30=81.1 Ans.