
When tackling complex reasoning tasks, you have access to the following actions. Use them as needed to progress through your thought process.

[ASSESS]

[ADVANCE]

[VERIFY]

[SIMPLIFY]

[SYNTHESIZE]

[PIVOT]

[OUTPUT]

You should strictly follow the format below:

[ACTION NAME]

# Your action step 1

# Your action step 2

# Your action step 3

...

Next action: [NEXT ACTION NAME]


system
Given the sequence ${a_n}$ where $a_{1}= \frac {3}{2}$, and $a_{n}=a_{n-1}+ \frac {9}{2}(- \frac {1}{2})^{n-1}$ (for $n\geq2$).
(I) Find the general term formula $a_n$ and the sum of the first $n$ terms $S_n$;
(II) Let $T_{n}=S_{n}- \frac {1}{S_{n}}$ ($n\in\mathbb{N}^*$), find the maximum and minimum terms of the sequence ${T_n}$.

Present the answer in LaTex format: \boxed{Your answer}
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