Answer:
7
Step-by-step explanation:
Let the missing number of the data be x.
[tex] \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[/tex]
Thus, the missing number of the data is 7.
