How to compare two columns and show an average basis?

Guys,

how do I in a comparison between two columns? More specifically I want to know the average temporality of zeros in column B when the A column shows the time in seconds.

[]

A
0.4000
0.4100
0.4200
0.4300
0.4400
0.4500
0.4600
0.4700
0.4800
0.4900
0.5000
0.5100
0.5200
0.5300
0.5400
0.5500
0.5600
0.5700
0.5800
0.5900
0.6000
0.6100
0.6200
0.6300
0.6400
0.6500
0.6600
0.6700

B
5.06
0
0
0
0
0
5.06
5.06
7.7
7.7
7.7
7.7
7.7
5.06
8.47
5.06
5.06
5.06
5.06
5.06
5.06
0
8.47
26.29
154.22
323.07
405.24
465.41

[Image Analyst]

What is your definition of "average temporality"???

[Hugo Souza]

Which time (values) are in the same line as zeros.

Answer 1

[Walter Roberson]

A(B==0)