Reference no: EM132287665
Probability With Applications Assignment -
Q1. Suppose a frog jumps among lily pads 1, 2 and 3 spends an exponentially distributed length of time on lily pad i with mean 4 - i hours. The frog jumps to the higher numbered unoccupied lily pad if the frog rolls anything but a 6. If a 6 comes up, the frog jumps to the lower numbered unoccupied lily pad. What is the generator and stationary distribution for Xt where Xt is the frog's location at time t?
Q2. Suppose we have 3 machines. Each machine breaks down according to a Poisson process with rate α = 2 per hour. The time it takes to repair a machine is exponentially distributed with rate µ = 3 per hour. A broken machine is costing us $100 per hour. Each repair-person on staff costs us $50 per hour whether working or idle. Would it be better to have 1 or 2 people repairing machines?
Q3. Suppose we have a gas station with two gas pumps. Cars arrival according to a Poisson process with rate 12/hour, but they may not stop for gas if the station is too busy. The length of time for a car to get gas is exponentially distributed with mean 5 minutes. If an arriving driver sees either 0 or 1 customers in the system, the driver stops for gas. Drivers who see 2 or 3 customers in the system stop for gas with probability 1/2. Drivers who see 4 or more customers in the system, do not stop for gas. Let Xt be the number of cars in the gas station at time t.
(a) What is the state space and generator?
(b) Determine L and Lq.
(c) Determine W and Wq for those customers that get gas.
(d) What fraction of customers are lost?
Q4. Suppose we have a large parking lot-pretend it can hold an unlimited number of vehicles. Suppose cars arrive according to a Poisson process with arrival rate λ > 0. Suppose each car remains in the lot for an exponentially distributed length of time with mean 1/µ. When does the stationary distribution exist, and when it exists, what is the stationary distribution of the number of cars in the lot?