
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
An ellipse $\frac {x^{2}}{a^{2}}+ \frac {y^{2}}{b^{2}}=1$ (where $a>b>0$) intersects the positive x-axis and y-axis at points A and B respectively. The distance from the origin O to the line AB is $\frac {2 \sqrt {5}}{5}$, and the eccentricity of the ellipse is $\frac {\sqrt {3}}{2}$.
(Ⅰ) Find the equation of the ellipse.
(Ⅱ) A line $l$ passing through the point $P(0, \frac {5}{3})$ intersects the ellipse at two distinct points M and N. Determine the range of the y-intercept of the perpendicular bisector of the line segment MN on the y-axis.

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