The lifetime of lightbulbs that are advertised to last for 3500 hours are normally distributed with a mean of 3700 hours and a standard deviation of 150 hours. What is the probability that a bulb lasts longer than the advertised figure? Probability =

Concentrations of pollutants produced by chemical plants historically are known to exhibit behavior that resembles a lognormal distribution. This is important when one considers issues regarding compliance with government regulations. Suppose it is assumed that the concentration of a certain pollutant, in parts per million, has a lognormal distribution with parameters mean = 3.2 and std. dev. = 1. What is the probability that the concentration exceeds 7.5 parts per million?

The time until recharge for a battery in a laptop computer under common conditions is normally distributed with mean of 275 minutes and a standard deviation of 50 minutes. What is the probability that a battery lasts more than four hours? (Round the answer to 3 decimal places.)

A tire company makes tires that have a normal distribution with a mean of 65,000 miles with a standard deviation of 3000 miles prior to needing replacement. Find the probability that a tire lasts between 60,500 to 69,500 miles.