Which of the "Seven QC Tools" would be most useful in addressing each of the following situations?

Which of the "Seven QC Tools" would be most use­ful in addressing each of the following situations? Explain your reasoning.

1. A copy machine suffers frequent paper jams and users are often confused as to how to fix the problem.
2. The publication team for an engineering depart­ment wants to improve the accuracy of its user documentation but is unsure of why documents are not error-free.
3. A bank needs to determine how many teller posi­tions, drive-through stations, and ATM machines it needs for a new branch bank in a certain busy location. Its information includes the average numbers and types of customers served by other similar facilities, as well as demographic informa­tion to suggest the level of customer traffic in the new facility.
4. A contracting agency wants to investigate why they had so many changes in their contracts. They believe that the number of changes may be related to the dollar value of the original contract or the days between the request for proposal and the contract award.
5. A travel agency is interested in gaining a better understanding of how call volume varies by time of year in order to adjust staffing schedules.