The distribution of passenger vehicle speeds traveling on theInterstate 5 Freeway (I-5) in California is nearly normal with amean of 74.9 miles/hour and a standard deviation of 6.5miles/hour.
(a) What proportion of passenger vehicles travel slower than 78miles/hour?
(b) What proportion of passenger vehicles travel between 57 and 83miles/hour?
(c) How fast do the fastest 10% of passenger vehicles travel?miles/hour
(d) Find a value k so that 45% of passanger vehiclestravel at speeds within k miles/hour of 74.9mph.k=
(e) The speed limit on this stretch of the I-5 is 70 miles/hour.Approximate what percentage of the passenger vehicles travel abovethe speed limit on this stretch of the I-5.
