Question

The mean of 100 observations is 40. The 9

th observation is 30. If this is

replaced by 70 keeping all other observations same, find the new mean.​

Answer 1

Answer:

Mean of 100 observations is 40. If the 9th observation is 30 and is replaced by 70 keeping all other observations same. Hence, the correct alternative answer is (B).

Step-by-step explanation:

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Answer 2

Answer:

Step-by-step explanation:

We have,

Mean of 100 observations is 40.

Total sum of observations=100×40=4000

If the 9th observation is 30 and is replaced by 70 keeping all other observations the same.

New, total sum of observations=4000−30+70=4040

So, the new mean=  

100

4040

​

=40.4