If an American household were chosen at random and asked how many tablet computers it owned, here are the probabilities as determined by a recent survey: Number of tablet computers 0 1 2 3 Probability 0.20 0.64 0.12 0.04 What is the probability that a randomly chosen household owns fewer than two tablet computers

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?