To determine the equation that represents the graph, we need to examine the relationship between the variables on the graph, which shows Typed Words in Essay on the y-axis and Minutes on the x-axis.

1. Identifying the slope (rate of change):
   We can observe that the graph has a straight line starting from the origin, which implies a proportional relationship. Let's calculate the slope by picking two points on the line. For instance:

   • At (4, 80): in 4 minutes, 80 words are typed.
   • At (8, 160): in 8 minutes, 160 words are typed.

   Slope $m = \frac{\Delta y}{\Delta x} = \frac{160 - 80}{8 - 4} = \frac{80}{4} = 20$.

   So, the slope $m$ is 20, meaning Sara types 20 words per minute.

2. Writing the equation:
   Since the line passes through the origin, the equation has the form $y = mx$. Substituting $m = 20$: $y = 20x$

   where $y$ is the number of words typed, and $x$ is the time in minutes.

The equation representing the graph is: $y = 20x$

Would you like more details or have any questions about this solution?

Here are five related questions to explore further:

1. How would the equation change if Sara typed faster, say 30 words per minute?
2. How can we determine if a relationship is proportional just by looking at a graph?
3. What would the y-intercept represent if the line didn’t start at the origin?
4. How would we calculate the total words typed in a specific number of minutes, like 15 minutes, using this equation?
5. If Sara took a break and resumed typing, how would that appear on the graph?

Tip: In proportional relationships, the graph always passes through the origin (0,0) and has a constant slope, representing the rate.