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Mean and standard deviations of 10 obser...

Mean and standard deviations of 10 observations are 20 and 2 respectively. If p `(p ne 0)` is multiplied to each observation and then q `(q ne 0)` is subtracted then new mean and standard deviation becomes half of original value . Then find q

A

`-20`

B

`-5`

C

10

D

`-10`

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