Question

7. The mean of 15 observations is 32. Find the
resulting mean, if each observation is :
(i) increased by 3 (ii) decreased by 7
(iii) multiplied by 2 4 ) divided by 0.5​

Answer 1

Answer:

(i) 35

(ii) 25

(iii) 64

(iv) 16

Explanation:

(i) If each observation is increased by 3 then the sum will increase by 3 x 15.

So original sum = 15 x 32 = 480

New sum = 480 + 45 = 525

So new mean = 525/15 = 35

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(ii) If each observation is decreased by 7 then the sum will decrease by 15 x 7.

Original sum = 480

New sum = 480 - 105 = 375

New Average = 375/15 = 25

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(iii) If each observation is multiplied by 2 then the entire sum will be multiplied by 2.

Original sum = 480

New sum = 480 x 2 = 960

New Average = 64

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(iv) If each observation is divided by 0.5 then the entire some will be halved

Original Sum = 480

New sum = 480 x 0.5 = 240

New average = 16

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Hope it helps!

Thank you for the question