The missing number is 16
Solution:
Given that mean of data is 18
Let "x" be the missing number
The data set is:
21, 11, x , 27, 22, 13, 16
Sum of data set = 21 + 11 + x + 27 + 22 + 13 + 16
Sum of data set = 110 + x
The mean is given by formula:
[tex]Mean = \frac{\text{sum of all numbers}}{\text{total numbers in data set}}[/tex]
Substituting the values we get,
[tex]18 = \frac{110+x}{7}\\\\126 = 110 + x\\\\x = 126 - 110\\\\x = 16[/tex]
Thus the missing number is 16
