We know that the y-intercept of our equation is -2, so our current equation is: y = mx - 2. Now we have to find m, which is the slope. Now, we plug in the points into the equation y = mx - 2, and we get 12 = 4m - 2. Thus, m is 3.5. Our final equation is y = 3.5x - 2.
The probability that Helen will roll a 4 is 1/6 the probability that she will get tails is 1/2. Multiply those two events together to find the probability of P(A and B)