The graph shows the number of cycles of a crosswalk signal during the day and during the night.


Answer:
Step-by-step explanation:
a). Since, both the lines are passing through origin (0, 0) y-intercept of the lines are zero.
For day periods,
Let the equation is, y = mx
Since, this line passes through (2, 80),
80 = 2m
m = 40
Therefore, equation for the day periods will be,
y = 40x
For night periods,
Let the equation is, y = mx
Since, this lines passes through (3, 90),
90 = 3m
m = 30
Therefore, equation of the line is,
y = 30x
b). For x = 6 hours,
Number of cycles in the day (y) = 40 × 6 = 240
Number of cycles in the night (y) = 30 × 6 = 180
Therefore, difference in the cycles in day and night = 240 - 180 = 60