Find the indicated probabilities using the geometric distribution, the Poisson distribution, or the binomial distribution Then determine if the events are unusual. If convenient, use the appropriate probability table or technology to find the probabilities.
A football player completes a pass $63.1 \%$ of the time. Find the probability that (a) the first pass he completes is the second pass, (b) the first pass he completes is the first or second pass, and (c) he does not complete his first two passes.
(a) $\mathrm{P}$ (the first pass he completes is the second pass) = (Round to three decimal places as needed)

Step 1 ：The problem is asking for the probability that the first successful pass is the second pass. This means that the first pass must be unsuccessful and the second pass must be successful. This is a geometric distribution problem. The geometric distribution gives the probability that the first occurrence of success requires k independent trials, each with success probability p. If the probability of success on each trial is p, then the probability that the kth trial (out of k trials) is the first success is \((1-p)^{(k-1)}*p\). In this case, p = 0.631 (the probability of a successful pass) and k = 2 (the first successful pass is the second pass).

Step 2 ：Substitute the given values into the formula: \((1-p)^{(k-1)}*p\).

Step 3 ：Substitute p = 0.631 and k = 2 into the formula to get the probability.

Step 4 ：The probability that the first pass he completes is the second pass is approximately \(0.233\).

Step 5 ：Final Answer: The probability that the first pass he completes is the second pass is \(\boxed{0.233}\).