The loudness, cap l , measured in decibels (Db), of a sound intensity, cap i , measured in watts per square meter, is defined as cap l is equal to 10 log the fraction with numerator cap i and denominator cap i sub 0 , where cap i sub 0 is equal to 10 to the negative 12 power and is the least intense sound a human ear can hear. What is the approximate loudness of a rock concert with a sound intensity of 10 inverse ?