He equation for the line of best fit is y = 0.39x + 15.89. which of the following statements is true for the above graph?

The given equation is a slope intercept form of a line. In which,

y = mx + b

where: y = y coordinate
            x = x coordinate
            m = slope
            b = y-intercept

In the equation, y = 0.39x + 15.89. The y-intercept is 15.89 or approximately 16. Meaning at x = 0, there's already approximately 16 dogs visiting at the park.

Therefore, the answer is the last statement.

ANSWER: The y-intercept of the line is 15.89, meaning that on the day the dog park opened, there were about 16 dogs visiting the park.