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The mean of a set of 20 observations is ...

The mean of a set of `20` observations is `8` an another set of `30` observations is `10`. The mean of combined set is ________.

A

`9.2`

B

`10.8`

C

`11.2`

D

`9.8`

Text Solution

Verified by Experts

The correct Answer is:
A
The mean of set of 20 observations is 8.
Sum of the observations = `20 xx 8 = 160`
The mean of another set of 30 observations is 10
Sum of the observations = `30 xx 10 = 300`
Total number of observation = 20 + 30 = 50
Total sum of observations = 460
Combined mean `= (460)/(50) = 9.2`
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