You can used AVERAGE or AVERAGEA depending on your requirement.
AVERAGE is used if all data points are number only.
AVERAGEA function is used if all non-blank fields (text or number) should be included while calculating mean.
Syntax: AVERAGE (RANGE); AVERAGEA (RANGE)
For example shown below:
AVERAGE (B1:B16) = SUM (B1: B16)/COUNT (B1: B16)=30/11=2.727 (30/11)
AVAERAGA (B1:B16) = SUM (B1:B16) / COUNTA (B1:B16) = 30 / 15 = 2
If the data set doesn’t have any text then AVERAGE will be equal to AVERAGEA as COUNT will be equal to COUNTA.