Question

The mean value of 25 numbers is 70 .If7 is added to thedata the new mean is

Answer 1

Answer:

Answer:-

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Let 'n' be the number of observations whose mean = 40.

total of n values.

Two more items of values 50 and 64 are added therefore, total of (n + 2) values :

Now new mean is 42.

\ New

\

\ 42n + 84 = 40n + 114

\ 2n = 30

\ n = 15

Therefore, the number of items in the original data = 15.

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Hope it helps you dear!

Answer 2

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Answer:-

Let 'n' be the number of observations whose mean = 40.

total of n values.

Two more items of values 50 and 64 are added therefore, total of (n + 2) values :

Now new mean is 42.

so,

42n + 84 = 40n + 114

2n = 30

n = 15

Therefore, the number of items in the original data = 15.

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