Two fair dice are rolled 5 times. Let the random variable x represent the number of times that the sum 9 occurs. The table below describes the probability distribution. Find the value of the missing probability.

x P(x)

0 0.554928957306643

1 0.346830598316652

2 0.086707649579163

3 0.0108384561973954

4 ?

5 1.69350878084303e-05

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?