On a scatterplot with a line of best fit, each dot shows an actual result, while the line predicts a result at the same -value. If the actual result exceeded the prediction, the dot is above the line. Compare vertical gaps, not the dots’ heights or their positions from left to right.
Hints
- Hint 1
A residual is actual time minus predicted time at the same delivery distance. A positive residual means the dot is above the line. Which labeled dots meet that condition?
- Hint 2
Compare the vertical gaps for the dots above the line. Read each dot’s time and the line’s predicted time at the same distance, then subtract. Which gap is greatest?
Step-by-step
Compare actual times with the line
Step 1Look for dots above the line
No Desmos needed. Read the gaps from the scatterplot. A residual is actual time minus predicted time at the same distance. To exceed the prediction, a dot must be above the line. is below it, so cannot be the answer.
- Step 2
Measure the gaps for P and S
At , the dot shows minutes and the line shows . At , the dot shows and the line shows . Subtract predicted from actual for each residual:
- Step 3
Check R against those gaps
At , the dot shows minutes and the line shows . Find its vertical gap:
That residual is greater than the -minute gaps for and . Delivery exceeded its predicted time by the greatest amount. Choice C.