Are 4 and 16/5 proportional?

The decibel level of sound is 50 db greater on a busy street than in a quiet room where the intensity of sound is watt/m2. the level of sound in the quiet room is db, and the intensity of sound in the busy street is watt/m2. use the formula , where is the sound level in decibels, i is the intensity of sound, and is the smallest sound intensity that can be heard by the human ear (roughly equal to watts/m2).

Which of the following is most likely the next step in the series? a3z, b6y, c9x, d12w, е15v, f18u

Abus travels 36 miles in 45 minutes. enter the number of miles the bus travels in 60 minutes at this rate.