If the average of 1, 2, 4, 5, 6, 9, 9, 10, 12 and x is 7, what is the value of x?	Choose the correct choice from the following.
A) 7	B) 9	C) 11	D) 12	E) 13
Sum of the deviations of the numbers in the set from the mean is always zero   1, 2, 4, 5, 6, 9, 9, 10, 12   mean is 7   so the list is -6-5-3-2-1+2+2+3+5... this shud total to zero   but this is -5 , hence we need a number that is 5 more than the mean to get a +5 and make it zero   hence the answer is  7 + 5= 
<gadget id="calculator"> 7 + 5</gadget>
<output>12</output>
12   12
<result>D</result>
If the average of 1, 2, 4, 5, 6, 9, 9, 10, 12 and x is 7, what is the value of x?