Question

The meaning of the data set is 18. What number is missing? 21, 11,____, 27, 22, 13, 16

Answer 1

Finding the Mean

The mean of a data set is calculated by finding the sum of all the values and dividing it by the number of values there are.

Therefore, the mean of this data set is the following, letting x = the missing value:

`18=(21+11+x+27+22+13+16)/(7)`

Add all the values in the numerator:

`18=(110+x)/(7)`

Multiply both sides by 7:

`126=110+x`

Isolate x:

`x=16`

Therefore, the number 16 was missing.