
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
A certain school conducted a survey on the daily reading time of students during the summer vacation, as shown in the table below:

|         | Mean | Variance | Number of Students |
|---------|------|----------|--------------------|
| Grade 10 | $2.7$ | $1$ | $800$ |
| Grade 11 | $3.1$ | $2$ | $600$ |
| Grade 12 | $3.3$ | $3$ | $600$ |

Find the variance of the daily reading time for all students.

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