Questions from Engineering Statistics

Q: The exponential distribution is frequently applied to the waiting times between successes

The exponential distribution is frequently applied to the waiting times between successes in a Poisson process. If the number of calls received per hour by a telephone answering service is a Poisson r...

Q: When α is a positive integer n, the gamma distribution is

When α is a positive integer n, the gamma distribution is also known as the Erlang distribution. Setting α = n in the gamma distribution on page 195, the Erlang distributio...

Q: A manufacturer of a certain type of large machine wishes to buy

A manufacturer of a certain type of large machine wishes to buy rivets from one of two manufacturers. It is important that the breaking strength of each rivet exceed 10,000 psi. Two manufacturers (A a...

Q: Consider Exercise 9.9. Compute a 95% prediction interval

Consider Exercise 9.9. Compute a 95% prediction interval for the sugar content of the next single serving of Alpha-Bits. Exercise 9.9 Regular consumption of presweetened cereals contributes to tooth...

Q: According to a recent census, almost 65% of all households

According to a recent census, almost 65% of all households in the United States were composed of only one or two persons. Assuming that this percentage is still valid today, what is the probability th...

Q: A certain type of device has an advertised failure rate of 0

A certain type of device has an advertised failure rate of 0.01 per hour. The failure rate is constant and the exponential distribution applies. (a) What is the mean time to failure? (b) What is the p...

Q: In a chemical processing plant, it is important that the yield

In a chemical processing plant, it is important that the yield of a certain type of batch product stay above 80%. If it stays below 80% for an extended period of time, the company loses money. Occasio...

Q: For an electrical component with a failure rate of once every 5

For an electrical component with a failure rate of once every 5 hours, it is important to consider the time that it takes for 2 components to fail. (a) Assuming that the gamma distribution applies, wh...

Q: The elongation of a steel bar under a particular load has been

The elongation of a steel bar under a particular load has been established to be normally distributed with a mean of 0.05 inch and σ = 0.01 inch. Find the probability that the elongation is (a) above...

Q: The speed of a molecule in a uniform gas at equilibrium is

The speed of a molecule in a uniform gas at equilibrium is a random variable V whose probability distribution is given by where k is an appropriate constant and b depends on the absolute temperature...