Final answer:
The question involves statistics concepts such as expected value and probability. The expected number of students attending graduation from a random group of 22, given an 85% attendance rate, would be approximately 19 students. Detailed calculations or expectations cannot be provided for other parts without further context.
Step-by-step explanation:
The question requires an understanding of basic statistics and probabilities to provide an answer. It seems the student is asking for help with understanding expected values and probabilities related to random variables in different scenarios, whether it be the attendance of an event like graduation, students receiving a certain amount of financial aid, or the likelihood that institutions offer certain types of courses or services.
In the context given, the expected number of students who have received $250 or more cannot be determined without additional information about the distribution or the total amount of financial aid given. Nevertheless, in the scenario regarding graduation attendance, if we assume that about 85 percent of graduating students attend their graduation, and we have a group of 22 randomly chosen students, we can calculate the expected number of attending students by multiplying the total number of students by the probability of attendance. That is, 0.85 * 22, which is approximately 18.7, suggesting that roughly 19 students are expected to attend their graduation.