Points x and z are on a number line, and point y partitions line xz into two parts so that the ratio of the length of line segment xy to the length of line segment yz is 5: 7. the coordinate of x is 0.4, and the coordinate is of y is 5.8. what is the coordinate of z?

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?