Answer:
The value of a is 7.
Explanation:
To calculate mean, add all of the numbers in the set and divide by the number of terms in said set. There are 7 numbers in this set, so the equation can be set up as follows.
(4 + 10 + 3 + 6 + a + 9 + 10)/7 = 7
Simplify the terms on the top.
(42 + a)/7 = 7
Multiply both sides by 7.
42 + a = 49
Subtract both sides by 42.
a = 7.
Proof:
(4 + 10 + 3 + 6 + a + 9 + 10)/7 = 7
Substitute variable.
(4 + 10 + 3 + 6 + 7 + 9 + 10)/7 = 7
Add in the parenthesis.
49/7 = 7
Divide.
7 = 7.