The tifetime of a certain residential humidifier is normally distributed with a mean of 12 years and a standard deviation of 3 years. Find the probability that if one of these humidifiers is randomly selected, it will tast between 4.5 years and 7.5 years. a. 0.927 b. 0.067 c. 0.008 d. 0.061 e. None of there