
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
Three cylindrical tanks have identical volumes. The height of the tallest tank is five times the height of the shortest tank, whose radius is 15 units. The second taller tank is one-fourth as tall as the tallest tank. If the radius of the tallest tank is r units, find the radius of the tank which is one-fourth as tall as the tallest. Express your answer in simplest radical form.

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