The response time is the speed of page downloads and it is critical for a mobile Web site. As the response time increases, customers become more frustrated and potentially abandon the site for a competitive one. . Let X denote the number of bars of service. . Let Y denote the response time (to the nearest second) for a particular user and site. y = Response X = Number of Bars time(nearest of Signal Strength f(y ) second) 1 2 3 0.01 0.02 0.25 0.28 2 0.02 0.03 0.20 0.25 3 0.02 0. 10 0.05 0.17 4 0.15 0.10 0.05 0.30 f ( x ) 0.20 0.25 0.55 1.00 Find P(Y = 4 X = 1)