Alexander uses cupric chloride to etch circuit boards. He recorded the room temperature, in C. and the etching
im
rate, in of the cupric chloride.
min
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:
1
y = 2 +
What is the residual if the room temperature was 25 C and the cupric chloride had an etching rate of 5
im
min
?