The replacement times for DVD players are normally distributed with a mean of 7.1 years and a standard deviation of 1.5 years (data from Consumer Reports). What is the probability that a randomly selected DVD player will be replaced in less than 5 years?
In a city, it is estimated that the maximum temperature in June is normally distributed with a mean of 23º and a standard deviation of 5°. Calculate the probability of having a maximum temperature between 20° and 28°.