For a standard problem, do exactly what's asked.
For a complete data analysis problem, follow the principle of a good data analysis. Write a report no more than a total of 10 pages, everything (introduction, analyses, conclusions, figures, output and tables etc) included. The report must stand alone; ie. it is a self-contained mini article and must be readable by a person with some basic statistics knowledge. All figures and computer output used in the report must be referenced, numbered and discussed. Unexplained and unorganized computer output will result in a negative credit. In the case where there is a choice of methodology, present the analysis using an "optimal" method and justify your choice; there is no need to demonstrate redundant methods except mentioning their conclusion if appropriate.