1. The problem asks to estimate the correlation coefficient of a scatterplot showing a positive linear trend with moderate strength. 2. The correlation coefficient, denoted as $r$, measures the strength and direction of a linear relationship between two variables. 3. The value of $r$ ranges from $-1$ to $1$ where: - $r = 1$ means a perfect positive linear relationship, - $r = -1$ means a perfect negative linear relationship, - $r = 0$ means no linear relationship. 4. Since the scatterplot shows a positive linear trend with moderate strength, the correlation coefficient should be positive but not close to 1. 5. Therefore, the best estimate for the correlation coefficient is $1$ (positive), but since it is moderate strength, the exact value is less than 1 but positive. 6. The problem asks to write -1, 0, or 1, so the answer is $1$ indicating a positive correlation.