Step-by-step explanation:
recall in a linear equation expressed in the form
y = mx + b,
m represents the slope or the rate of change in the value of y for a unit change in the value of x
b represents the y-intercept (i.e the value of y when x = 0)
If you compare these definitions to what was given in the question, the rate of change in snowfall is given as 1/2 inches per hour. This is equivalent to the m value in our general equation above. Hence we can say that the rate of change in snowfall is equal to the slope of the graph.
The question also states that before the snow even started to fall (i.e when x=0 hours), there was already 8 inches on the ground. This is equivalent to the value of b in our general equation above. Hence we can say that the y-intercept is representative of the 8 inches that was already on the ground when the snow started falling.