If the average (arithmetic mean) of 8, 12, 15, 21, x, and 11 is 17, then what is x?
Q1. If the average (arithmetic mean) of 8, 12, 15, 21, x, and 11 is 17, then what is x?
Answer: 35
Explanation: Sum of all six values = 17×6 = 102; subtracting the known values (8+12+15+21+11 = 67) gives x = 35.