Remember you can do anything to an equation as long as you do it to both sides
a=age
500 reduced by 2 times a is equal to 388
500-2a=388
minus 500 both sides
-2a=-112
divide both sides by -2
a=56
you are 56
1 and 1/2 is the right one
The sample mean is the sum of the sample values divided by the number of them:
(7 +7 +10 +6 +9 +6 +8 +7.5 +8.5 +8)/10 = 77/10 = 7.7
The sample mean is 7.7.
Answer is 6. because 3x6 is 18
