Questions from Applied Statistics

Q: In a recent year, potentially dangerous commercial aircraft incidents (e

In a recent year, potentially dangerous commercial aircraft incidents (e.g., near collisions) averaged 1.2 per 100,000 flying hours. Let X be the number of incidents in a 100,000-hour period. (a) Just...

Q: The length of a time-out during a televised professional football

The length of a time-out during a televised professional football game is normally distributed with a mean of 84 seconds and a standard deviation of 10 seconds. If the network runs consecutive commerc...

Q: Car security alarms go off at a mean rate of 3.

Car security alarms go off at a mean rate of 3.8 per hour in a large Costco parking lot. Find the probability that in an hour there will be (a) no alarms; (b) fewer than four alarms; and (c) more than...

Q: Demand for residential electricity at 6:00 p.m.

Demand for residential electricity at 6:00 p.m. on the first Monday in October in Santa Theresa County is normally distributed with a mean of 4,905 MW (megawatts) and a standard deviation of 355 MW. D...

Q: Past insurance company audits have found that 2 percent of dependents claimed

Past insurance company audits have found that 2 percent of dependents claimed on an employee’s health insurance actually are ineligible for health benefits. An auditor examines a random sample of 7 cl...

Q: Procyon Manufacturing produces tennis balls. Their manufacturing process has a mean

Procyon Manufacturing produces tennis balls. Their manufacturing process has a mean ball weight of 2.035 ounces with a standard deviation of 0.03 ounce. Regulation tennis balls are required to have a...

Q: A law enforcement agency processes 500 background checks for firearms purchasers.

A law enforcement agency processes 500 background checks for firearms purchasers. Fifty applicants are convicted felons. Through a clerk’s error, 10 applicants are approved without checking for felony...

Q: Tests show that, on average, the Li-ion Hitachi

Tests show that, on average, the Li-ion Hitachi stick driver can drive 207 drywall screws on a single charge. Bob needs to drive 230 drywall screws. If the standard deviation is 14 screws, find the pr...

Q: The time it takes to give a man a shampoo and haircut

The time it takes to give a man a shampoo and haircut is normally distributed with mean 22 minutes and standard deviation 3 minutes. Customers are scheduled every 30 minutes. (a) What is the probabili...

Q: If the weight (in grams) of cereal in a box

If the weight (in grams) of cereal in a box of Lucky Charms is N(470,5), what is the probability that the box will contain less than the advertised weight of 453 g?