
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
Among the following random events, the random variable $X$ follows a hypergeometric distribution in \_\_\_\_\_\_\_\_. (Fill in the serial number)

① Tossing a coin 3 times in a row, the number of times the head appears is denoted as $X$;

② Selecting 5 outstanding student leaders from 10 students, consisting of 7 males and 3 females, and denoting the number of females as $X$;

③ A shooter has a hit rate of 0.8, now shooting at a target once, and the number of hits is denoted as $X$;

④ In a box, there are 4 white balls and 3 black balls, drawing 1 ball each time without replacement, and $X$ is the number of draws until the first black ball is drawn.

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