Which step comes last when using the divide-center method to find the trend line on a scatterplot? Approximate the center of the cluster located on the left side of the line, and repeat for the right side of the line. Connect the two centers to produce the trend line. Disregard all outliers. Draw a vertical line so that each side has the same number of data points.​

Statements reasons 1. ab ? cd; ad ? bc 1. given 2. ac ? ac 2. reflexive property 3. ? adc ? ? cba 3. ? 4. ? dac ? ? bca; ? acd ? ? cab 4. cpctc 5. ? dac and ? bca are alt. int. ? s; ? acd and ? cab are alt. int. ? s 5. definition of alternate interior angles 6. ab ? cd; ad ? bc 6. converse of the alternate interior angles theorem 7. abcd is a parallelogram 7. definition of parallelogram what is the missing reason in step 3?