Question

the mean of 50 observation was 250.it was detected on checking that the value of 165 was wrongly copied as 115 for computation of man. find the correct mean please answer this fast .i will mark u as brainless

Answer 1

Mean of 50 =(x1+x2-----x50)/50

250=(x1+x2----x50)/50

250*50={x1+x2-----x50}

12500={x1+x2----x50}

Then the sum of incorrect 50 observations is 12500

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If 165 was written wrong as 115

Then the sum of the given observation will be

12500-115+165

12385+165

12550

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Then the correct mean is

Mean =(x1+x2---x50)/50

Mean =(12550)/50

Mean =251

Then the correct mean is 251

I hope this much will help you

- by ABHAY

Answer 2

Given that total number of observations = 50.

Given that Mean of all observations = 250.

So, Sum of all observations = 250 * 50

                                               = 12500.


Given that the value of 165 was wrongly copied as 115 for computation of man.

= 12500 + (165 - 115)

= 12500 + 50

= 12550.


Therefore the correct mean of all observations = 12550/50

                                                                                = 251.


Hence, the correct mean = 251.


Hope this helps!