Question

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

Answer 1

Answer:

7

Step-by-step explanation:

Let the missing number of the data be x.

$\because mean = \frac{3 + 4 + x + 7 + 2 + 1}{6} \\ \\ \therefore 4 = \frac{17 + x }{6} \\ \\ \therefore 4 \times 6 = 17 + x \\ \\ \therefore 24 - 17 = x \\ \\\therefore x = 7$

Thus, the missing number of the data is 7.