Question

The mean of 8 observations was found to be 30. Later it was detected that one observation 64 was mistakenly read as 24. Find the correct mean.

Answer 1

Solution:




Mean of 8 observations= 30


Sum of  8 observations= 30× 8= 240


Correct sum of 8 observations = 240 - (wrongly read ) + correct number


Correct sum of 8 observations = 240 - 24+ 64

= 240+64-24= 304 - 24 = 280


Correct Mean= correct Sum of  8 observations/ total number of observations


Correct mean = 280 /8= 35


Correct mean = 35

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Answer 2

Hi friend,

Your answer:


Mean of 8 observations= 30

Sum of  8 observations= 30× 8= 240

Correct sum of 8 observations = 240 - 24+ 64

                                                 = 240+64-24= 304 - 24

                                                 = 280

Now,

Correct mean = 280 /8= 35


Hope it helps!