Question

The mean of three numbers is 10. The mean of other four numbers is 12. Find the mean of all the numbers.



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Answer 1

Answer:

Correct option is B)

Given, Mean of 3 no's =10.

Then, total of 3 no's is =10×3=30.

Also, Mean of other 4 no's is 12.

Then, Total of 4 no's is =12×4=48.

∴Total  of 4+3=7 numbers is 48+30=78.

We know, Mean is given by,

Mean=Total number of elementsSum of the elements.

Hence, mean of 7 numbers is 778=11.15 .

Therefore, option B is correct.

Answer 2

Answer:

$\huge \dag \sf \green{question}$

The mean of three numbers is 10. The mean of other four numbers is 12. Find the mean of all the numbers.

$\huge \sf \blue{answer} \downarrow$

Mean of three numbers=10

Sum of observations = mean×number of observations

=10×3=30

Mean of other four numbers = 12

Sum of observations = 12×4=48

Now,

Sum of all observations = 30+48=78

Total numbers of observations =7

Arithmetic mean=

$\sf \frac{sum \: of \: all \: observations}{total \: number \: of \: observations} \\ \\ \sf \: mean = \frac{78}{7} \\ \\ \red{\boxed{ \blue{ = 11.14}}}$

Hope it helps you from my side

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