The image shows a WebWork interface where you're asked to use the trapezoid rule with four subintervals to estimate the area under the graph of a function $f(x)$ from $x = 1$ to $x = 9$.

To solve this using the trapezoid rule, we first need to apply the formula for the trapezoidal rule:

$T_4 = \frac{b - a}{4} \left( f(a) + 2 \sum_{i=1}^{3} f(x_i) + f(b) \right)$

Where:

• $a = 1$ and $b = 9$ (the interval),
• The subintervals are divided by 4,
• $x_1, x_2, x_3$ are the points where the function is evaluated between $a$ and $b$.

We can estimate the values of $f(x)$ at these points by referring to the graph. Would you like me to guide you through how to calculate the points from the graph, or would you like to provide specific values for the function at these points?