In order to solve this problem, you should
Make an Equation
The equation is
x+x+2+x+4+x+6+x+8+x+10= 204
Simplify if possible.
6x+30= 204
Isolate the Variable
6x+30-30=204-30
6x=174
Make the Variable Equal One
6x÷6= 174÷6
x=29
1st Number= 29
2nd Number= 29+2
3rd Number= 29+4
4th Number= 29+6
5th Number= 29+8
6th Number= 29+10
You are trying to find the 4th number
so 29+6=
35
The answer is 35.
Hope this helps.