\( \beta_1 \) is the slope of the regression line, indicating how much \( y \) changes for a one-unit change in \( x \).

In regression analysis, β1 represents the slope of the regression line. It indicates how much the dependent variable (the outcome you're trying to predict) is expected to change for every one-unit increase in the independent variable (the predictor). In simple terms, \( \beta_1 \) tells you the strength and direction of the relationship between the two variables: if it's positive, the dependent variable increases as the independent variable increases; if it's negative, the dependent variable decreases as the independent variable increases.