Question

If the mean and standard deviation of 75 observations is 40 and 8 respectively, find the new mean and standard deviation if 
1) Each observation is multiplied by 5.
2) 7 is added to each observation.

( Need the answer within 1 hour plz. and don't write anything if you don't know the answer)​

Answer 1

Answer:

If the mean and standard deviation of observations x

1

,x

2

...,x

n

are

X

and σ respectively, then the mean and standard deviations of ax

1

,ax

2

...,ax

n

are a

X

and ∣a∣σ respectively.

∴ New mean=8×3=24 and, New standard deviation=3×4=12.

Answer 2

Answer:

If the mean and standard deviation of observations x

1

,x

2

...,x

n

are

X

and σ respectively, then the mean and standard deviations of ax

1

,ax

2

...,ax

n

are a

X

and ∣a∣σ respectively.

∴ New mean=8×3=24 and, New standard deviation=3×4=12.

Explanation:

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