ASK YOUR TEACHER A traffic engineer believes that the number of cars passing through a certain intersection between 2-6 pm on weekdays follows a normal distribution with mean 750. A new highway is opened, and it is hypothesized that the number of cars passing through the intersection will change as a result. A sample of 15 weekdays is taken, and the average number of cars passing through the intersection is computed to be 720, with a sample standard deviation of 42. Decide whether this reduction in traffic is statistically significant, using significance level