The scale of the graph makes it difficult to read the y-intercept, we choose to do part B first.
B. The graph appears to go through the point (1, 5) and (5, 12), so will have equation
.. y = (12-5)/(5-1)*(x -1) +5
.. y = (7/4)x +3 1/4 . . . . . . . . . . equation of the line
Then for x=13, you have
.. y = (7/4)*13 +3 1/4
.. y = 26
The predicted number of matches won is 26.
A. From part B, the y-intercept is 3 1/4 (looks approximately like that on the graph). It represents the number of matches won if students don't practice at all.