Respuesta :

Answer:

Step-by-step explanation:

First add what you have.

Sum = 5 + 7 +7+8 + x + 5 + 4 +3 + 1 +2

Sum =  x + 42

Now when you divide this by the number of terms, you get

(x + 42) / 10

The answer is 4.5

(x + 42) / 10 = 4.5                 Multiply by 10

x + 42 = 4.5 * 10

x + 42 = 45                           Subtract 42

x = 45  - 42

x = 3