1. The useful life of an electrical component is exponentially distrbuted with a mean of 2500 hours.

a) What is the probability the circuit will last more than 3000 hrs.

b) What is the probability the circuit will last between 2500 and 2750 hours

c) What is the probability the circuit will fail within the first 2000 hrs.

2. When only the value added time is considered the time it takes to build a laser printer is thought to be uniformly distributed between 8 and 15 hrs.

a) What are the chances that it will take more than 10 value added hours to build a printer.

b) How likely is it that a printer will require less than 9 value added hours.

c) Suppose a single customer orders two printers, what is the probability that the first and second printer each will require less than 9 value added hours to complete.

3. Average credit card debt is $9312. Assume the debt has a normal distribution with standard deviation of $3000

a) Determine the percentage of household with credit card debt of mare than.$15000

b) One household has credit card debt that is at the 95 percentile. Determine its credit card debt.