The waiting time until service at a hospital emergency department is modeled with the pdf f(x) = (1/9)x for 0(a) Probability the wait is less than 4 hours
(b) Probability the wait is more than 5 hours
(c) Probability the wait is less than or equal to 30 minutes
(d) Waiting time that is exceeded by only 10% of patients
(e) Mean waiting time