Josh is preparing for an exam by completing practice tests that have different numbers of questions. For each practice test, he notes the number of questions and the time it takes him to complete the test.
Next, Josh creates a scatter plot and draws a trend line to fit the data. To see how well the trend line represents the data, Josh draws black lines to represent the distance each data point lies away from the trend line.
What is the sum of the residuals for all the points?
A. 97
B. 19
C. 39
D. 58