
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 following five statements are given:
① The smaller the standard deviation, the smaller the fluctuation in sample data;
② Regression analysis studies the independence between two related events;
③ In regression analysis, the predicted variable is determined by both the explanatory variable and random error;
④ The coefficient of determination, $R^2$, is used to characterize the regression effect; the larger the $R^2$, the better the fit of the regression model.
⑤ For the observed value $k$ of the random variable $K^2$ for categorical variables $X$ and $Y$, the smaller the $k$, the less confident one can be about the relationship between $X$ and $Y$.
Among these statements, the correct ones are (please write the numbers of the correct statements on the line).

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