
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
The arithmetic mean of four numbers is 10. If one of these numbers is removed, the arithmetic mean of the remaining three increases by 1. If a different number is removed instead, the arithmetic mean of the remaining three increases by 2. If a third number is removed, the arithmetic mean of the remaining three increases by 3. By how much will the arithmetic mean of the remaining three numbers change if the fourth number is removed?

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