Calculate average times

[tarumatu]

Hi, i'm having a hard time working out average pageview times on a website. I've already had a look on a number of posts but nothing seems to work, i've tried right-clicking the data range and formatting to time or custom as hh:mm:ss as my times are displayed as hours mins secs. I've tried the standard =average(data range), as well as =TEXT(AVERAGE(a1:a1000),"[hh]:mm:ss").Each time i get an error #DIV/0!. I dont understand why it doesnt work, could it be because the data range is from over 1500 rows of data? Can anyone help?

 

[oldbrewer]

can you put say 10 rows onto google sheets ?