Write an equation in slope-intercept form of the trend line.

y = ???

The graph shows a line at Y axis on 12, going up to 21 on the Y axis.

To find the equation in slope-intercept form, we first need to determine the slope of the line.

Slope (m) = (change in y) / (change in x)
Slope (m) = (21 - 12) / (0 - 0)
Slope (m) = 9 / 0

Since the change in x is 0, the slope is undefined and the line is vertical.

Therefore, the equation in slope-intercept form of the trend line would be:
x = 0