A tally records the value 1 twice, the value 2 three times and the value 3 five times. What is the mean of these ten values? Enter the mean as a decimal.
Correct answer
2.3
Explanation
The ten values total 2 x 1 + 3 x 2 + 5 x 3 = 23, and 23 divided by the 10 values gives 2.3. Averaging the three listed values as 1 plus 2 plus 3 over 3 returns 2, but that treats every value as if it had occurred once, while the tally says the value 3 occurred five times.