Ms. Aquina has just had a biopsy on a possibly cancerous tumor. Notwanting to spoil a weekend family event, she does not want to hear any bad news in the next few days. But if she tells the doctor to call only if the news is good, then if the doctor does not call, Ms. Aquina can conclude that the news is bad. So, being a student of probability, Ms. Aquina instructs the doctor to flip a coin. If it comes up heads, the doctor is to call if the news is good and not call if the news is bad. If the coin comes up tails, the doctor is not to call. In this way, even if the doctor doesn’t call, the news is not necessarily bad. Let α be the probability that the tumor is cancerous; let be the conditional probability that the tumor is cancerous given that the doctor does not call.

a. Which should be larger, or β.

b. Find in terms of and prove your answer in part (a).