Use the following information for determining sound intensity. The level of sound , in decibels, with an intensity of I, is B=10 log10 10910(++) where Io is an intensity of 10-12 watt per square meter, corresponding roughly to the faintest sound that can be heard by the human ear. As a result of the installation of a muffler, the noise level of an engine was reduced from 88 to 73 decibels. Find the percent decrease in the intensity level of the noise due to the installation of the muffler. %