The time spent waiting in the line is approximately normally distributed. The mean waiting time is 7 minutes and the variance of the waiting time is 9. Find the probability that a person will wait for more than 13 minutes. Round your answer to four decimal places.

The graph shows the decibel measure for sounds depending on how many times as intense they are as the threshold of sound. noise in a quiet room is 500 times as intense as the threshold of sound. what is the decibel measurement for the quiet room? 20 decibels28 decibels200 decibels280 decibels