Question

If the mean is 4, what is the missing number of the data set: 3, 4, ___, 7, 2, 1.

Answer 1

7

Explanation:

Let the missing number of the data be x.

`\because mean = (3 + 4 + x + 7 + 2 + 1)/(6) \\ \\ \therefore 4 = (17 + x )/(6) \\ \\ \therefore 4 * 6 = 17 + x \\ \\ \therefore 24 - 17 = x \\ \\\therefore x = 7`

Thus, the missing number of the data is 7.