mean of 25 item is 32. each item is increased by 10, the new mean is;  [40, 32, 35, 25, 42]

Asked by Rony Joseph | 3rd Apr, 2014, 06:36: PM

Expert Answer:

n = 25, Mean = 32
L e t space x subscript 1 comma x subscript 2 comma...... end subscript x subscript 25 be the 25 items.
M e a n equals fraction numerator S u m over denominator T o t a l end fraction rightwards double arrow S u m space equals space M e a n space cross times T o t a l space equals 32 cross times 25 equals 800
Now, new numbers will be
x subscript 1 plus 10 comma space x subscript 2 plus 10 comma space....... space comma space x subscript 25 plus 10
Thus, mean of new numbers will be
 
M e a n equals fraction numerator left parenthesis x subscript 1 plus 10 right parenthesis plus left parenthesis x subscript 2 plus 10 right parenthesis plus......... plus left parenthesis x subscript 25 plus 10 right parenthesis over denominator 25 end fraction equals fraction numerator left parenthesis x subscript 1 plus x subscript 2 plus......... plus x subscript 25 right parenthesis plus 10 cross times 25 over denominator 25 end fraction equals fraction numerator S u m plus 250 over denominator 25 end fraction equals fraction numerator 800 plus 250 over denominator 25 end fraction equals 1050 over 25 equals 42

Answered by  | 4th Apr, 2014, 10:07: AM

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