"Seeing multiple stories about the same shark attack led people to believe that shark attacks are common because the stories came easily to mind. This is an example of what concept

availability heuristic

Explanation:

Availability heuristic is very useful and essential in decision making or taking. Most times in our decision making process, we tend to recur information or things that occurs a long time ago or a common phenomenon that suddenly appears in our thoughts and we base our decision at times by the outcome of those thoughts. Example is when phone theft I reported on TV constantly, you can infer mostly that it occurs in you area often that it does. In this type, you give power to the information and most times you overestimate the likelihood of it occuring.

6.3%

explanation:

the acceptance rate for yale university is 6.3%. this means that only 6 percent of people who apply actually get accepted!