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The mean of 6 numbers is 19. If two more numbers are included, the mean of the 8 numbers becomes 23. What is the sum of the two included numbers?

Solution

✅ Correct Option: 3

The mean of 6 numbers is 19. Two more numbers are included, making 8 numbers with a mean of 23.

The mean formula is:

Mean =Sum of all numbersNumber of values= \dfrac{\text{Sum of all numbers}}{\text{Number of values}}


For the original 6 numbers:

19=Sum of 6 numbers619 = \dfrac{\text{Sum of 6 numbers}}{6}

Sum of 6 numbers=19×6\text{Sum of 6 numbers} = 19 \times 6

Sum of 6 numbers=114\text{Sum of 6 numbers} = 114


For all 8 numbers:

23=Sum of 8 numbers823 = \dfrac{\text{Sum of 8 numbers}}{8}

Sum of 8 numbers=23×8\text{Sum of 8 numbers} = 23 \times 8

Sum of 8 numbers=184\text{Sum of 8 numbers} = 184


The sum of the 2 new numbers is the difference between the total sum of 8 numbers and the original sum of 6 numbers:

Sum of 2 new numbers=184−114\text{Sum of 2 new numbers} = 184 - 114

Sum of 2 new numbers=70\text{Sum of 2 new numbers} = 70

Therefore, the sum of the two included numbers is 7070.

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