Answer: Compound probability is equal to the probability of the first event multiplied by the probability of the second event
HOPE THIS HELPS
Slope = 4/6= 2/3
Intercept is -1 (I think just check with gradient on graph in doing in my head)
Y=MX+B
Y=2/3X-1 ( if my calculations add up
I believe the answer is 5 mph east