PLEASE HELP Alexander uses cupric chloride to etch circuit boards. He recorded the room temperature, in °C, and the etching
um
rate, in
min
, of the cupric chloride.
After plotting his results, Alexander noticed that the relationship between the two variables was fairly linear, so
he used the data to calculate the following least squares regression equation for predicting the etching rate from
the room temperature:
9 =21
What is the residual if the room temperature was 25°C and the cupric chloride had an etching rate of 5 um
min
- ?
um
min

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?