\( \square \% \) of the area lies below the mean.

In a **symmetric distribution**, such as the **normal (bell-shaped) distribution**, the mean and median are equal. This symmetry ensures that: - **50% of the area lies below the mean.** - **50% of the area lies above the mean.** So, for a normal distribution: \[ \boxed{50\%} \] This means that **50% of the data points fall below the mean value**. **Visual Representation:** Imagine the classic bell curve: ``` * * * * * * * ---------|--------- Mean * * * * * * * ``` Here, the vertical line represents the mean. The area under the curve to the left of this line is exactly half of the total area, confirming that **50% of the area lies below the mean**. **Note:** In **skewed distributions**, the percentage of area below the mean can differ from 50%, depending on the direction and degree of skewness. However, for symmetric distributions like the normal distribution, it's always 50%. Answer: 50 %