Loudness, or the intensity of sound, is measured in decibels. the sound level of a television is about 70 decibels, which is considered a safe hearing level. a food blender runs at 20 decibels higher than a tv, and a jet engine's decibel reading is 40 less than twice that of a blender. at this level, exposure can cause hearing loss. find the intensity of the sound of a jet engine.

Data from 2005 for various age groups show that for each $100 increase in the median weekly income for whites, the median weekly income of blacks increases by $105. also, for workers of ages 25 to 54 the median weekly income for whites was $676 and for blacks was $527. (a) let w represent the median weekly income for whites and b the median weekly income for blacks, and write the equation of the line that gives b as a linear function of w. b = (b) when the median weekly income for whites is $760, what does the equation in (a) predict for the median weekly income for blacks?