The mean of the numbers: 7, 21, 2, 17, 3, 13, 7, 4, 9, 7, 9 is 9.
The mean or the average is the quotient of the total values of a data set divided by the number of data values.
It is one of the measures of central tendency, including the median and the mode.
The mean can be computed using division operation, which involves the dividend, the divisor, and the quotient.
The total of the numbers = 99 (7, 21, 2, 17, 3, 13, 7, 4, 9, 7, 9)
The number of numbers = 11
The mean of the numbers = 9 (99 ÷ 11)
Thus, we can conclude that the mean or the average number is 9.