Questions from Engineering Statistics

Q: During a manufacturing process, 15 units are randomly selected each day

During a manufacturing process, 15 units are randomly selected each day from the production line to check the percent defective. From historical information it is known that the probability of a defec...

Q: An automatic welding machine is being considered for use in a production

An automatic welding machine is being considered for use in a production process. It will be considered for purchase if it is successful on 99% of its welds. Otherwise, it will not be considered effic...

Q: A car rental agency at a local airport has available 5 Fords

A car rental agency at a local airport has available 5 Fords, 7 Chevrolets, 4 Dodges, 3 Hondas, and 4 Toyotas. If the agency randomly selects 9 of these cars to chauffeur delegates from the airport to...

Q: According to a study published by a group of University of Massachusetts

According to a study published by a group of University of Massachusetts sociologists, approximately 60% of the Valium users in the state of Massachusetts first took Valium for psychological problems....

Q: Service calls come to a maintenance center according to a Poisson process

Service calls come to a maintenance center according to a Poisson process, and on average, 2.7 calls are received per minute. Find the probability that (a) no more than 4 calls come in any minute; (b)...

Q: An electronics firm claims that the proportion of defective units from a

An electronics firm claims that the proportion of defective units from a certain process is 5%. A buyer has a standard procedure of inspecting 15 units selected randomly from a large lot. On a particu...

Q: An electronic switching device occasionally malfunctions, but the device is considered

An electronic switching device occasionally malfunctions, but the device is considered satisfactory if it makes, on average, no more than 0.20 error per hour. A particular 5-hour period is chosen for...

Q: A company generally purchases large lots of a certain kind of electronic

A company generally purchases large lots of a certain kind of electronic device. A method is used that rejects a lot if 2 or more defective units are found in a random sample of 100 units. (a) What is...

Q: A local drugstore owner knows that, on average, 100 people

A local drugstore owner knows that, on average, 100 people enter his store each hour. (a) Find the probability that in a given 3-minute period nobody enters the store. (b) Find the probability that in...

Q: (a) Suppose that you throw 4 dice. Find the

(a) Suppose that you throw 4 dice. Find the probability that you get at least one 1. (b) Suppose that you throw 2 dice 24 times. Find the probability that you get at least one (1, 1), that is, “snake-...