
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
Randomly select 10 students from classes A and B of a certain school and measure their heights (unit: cm). The height data obtained are as follows:  
Class A: $170\ \ 179\ \ 162\ \ 168\ \ 158\ \ 182\ \ 179\ \ 168\ \ 163\ \ 171$  
Class B: $159\ \ 173\ \ 179\ \ 178\ \ 162\ \ 181\ \ 176\ \ 168\ \ 170\ \ 165$  
$(1)$ Calculate the sample variance of Class A;  
$(2)$ Find the $25\%$ percentile of the data in Class B.

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