Average calculations in Power BI get wrong

[SIH007_1]

I have an issue with the calculation of averages both within a table and a clustered column chart - the calculations are wrong and I don't have the slightest idea how to combat it. 
I have several levels in the table - same as in the chart. On the pic you see part of the numbers, the ones with an icon on the right are the bottom level, the bold ones within the red frame are supposed to show the average, so when I calculate the first 4 numbers I get an average of 2.975, not 3.1, for the bottom 4 numbers my average is also 2.975, not 2.8. Same with the green level, with my numbers it should also be 2.975. 
And my overall average is 3.0 whereas my table and column chart show 2.7. Is that a bug?

[v-yanjiang-msft]

Hi @SIH007_1 ,

Sorry I'm not sure how did you get the result, by a measure or simply selecting "Average" of the column, could you please describe more about the process?

Best regards,

Community Support Team _ Yan Jiang

[dsorci]

Are you doing averages off a detail or summary table? Sometimes a weighted average is needed if done at a summary level.