每月平均体重 - 图表 - Google 表格

Question

I have a dataset with weight on specific dates:

I have already made a graph of this, but I find it a little bit confusing:

There are no system when the measurement have been taken place. Meaning in some months there are a lot of data, and other months there are just 2,3 or even 0. So I want to turn this into average per month. I have found a way to get the data into average per month:

Combinding ArrayFormula:

=ARRAYFORMULA(IF(A3:A71 <> ""; YEAR(A3:A71) & "/" & MONTH(A3:A71); ""))

With Query:

=QUERY(A3:C64;"select C, avg(B) where C != '' group by C order by C"; 0)

Which outputs the following:

2020/10 81,6
2020/11 78,9
2020/12 77,4
2020/7  87,2
2020/9  83,4
2021/1  78,0
2021/3  75,6
2021/4  77,9
2021/5  79,6
2021/7  82,6
2021/8  82,3
2021/9  81,0

But there are at least two problems:

1. It is not sorted correctly
2. I am not able to make a graph of it as this is not formatted by date.

Any ideas how I can solve this problem succesfully? Can it be solved by ArrayFormula?

Please take a look at the spreadsheet:

https://docs.google.com/spreadsheets/d/1tcWMZZGL7MwJSJgqLlIVNghD-WiJEZJa8xO4mRrhF6A/edit?usp=sharing

Answer 1

Try this in cell D2:

=arrayformula(query({eomonth(A2:A;0)\B2:B};"select Col1,avg(Col2) where Col2 is not null group by Col1 label Col1 'Month'";1))

Set the chart range to D1:E64 .

You can format ColD to be 'mmm yy' or whatever you need.