Charles is looking to buy a classic Porsche. He compiles some online prices for a few classic Porsches: $38,000; $41,900; $42,100; $36,500; and $39,000. Is it more reasonable for Charles to use the mean or the median to get a reasonable estimated price for the car? What is a reasonable price for a classic Porsche (based on the values above)?

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?