IXL | Mean: find the missing number

Vivian has the following data:

If the mean is 15, which number could j be?

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Tina has the following data:

If the mean is 5, which number could m be?

The mean is the average of the numbers. You find the mean by adding the numbers together and then dividing by the number of numbers in the group.

There are 5 numbers in the group.

Try m = 5.

Find the sum of the numbers.

5 + 5 + 5 + 5 + 5 = 25

Divide by 5.

25 ÷ 5 = 5

When m = 5, the mean is 5.

Try m = 10.

Find the sum of the numbers.

5 + 5 + 5 + 10 + 5 = 30

Divide by 5.

30 ÷ 5 = 6

When m = 10, the mean is 6.

The mean is 5, so m = 5.

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