It looks like you're presenting relationships between variables, likely in the context of physics or mathematics. However, the notation seems a bit unclear. Let's clarify and interpret the expressions you've written.
1. **T2 ∝ a:** This means that T2 is proportional to `a`.
2. **T3 ∝ a2:** This indicates that T3 is proportional to the square of `a`.
3. **T2 ∝ a3:** This means T2 is also described as proportional to the cube of `a`.
4. **T ∝ a2:** This indicates that T is proportional to the square of `a`.
To clarify any contradictions or to consolidate the relationships, it would be helpful to know what these variables represent (e.g., what T means, what a represents).
If you're trying to establish a direct relationship between T2 and T3 or any other variable, you might also look for a common condition or scenario that ties them together—if that's your goal.
If you provide more context or specific equations tying these expressions together, I’d be happy to help further!