Portfolio Task 1 -
(A) Find three examples of statistical charts/diagrams/graphical data displays from business management publications/media/research etc. You should write a paragraph on each statistical chart etc, specifically with reference to Zelazny's presentation & interpretation framework covered in the course and in Zelazny's book (see course reading list in course guide) and discuss the following points: BOOK TO READ: Say it with Charts, Gene Zelazny, McGraw-Hill, 2007 Section 1 and Section 2
(B) Do your chosen examples follow Zelazny's framework for charts? If not, why not?
(C) Given the charts as they appear in your selection what would be effective messages for them?
(D) Produce new charts with effective messages to comply with Zelazny's framework where your selected charts do not follow the framework and hence incorrect. Approximate scales for your redrawn charts are acceptable.
No two charts should be similar in your selection of three charts.
(F) Find a suitable example and turn a routine statistical story into one which is more meaningful and with a much stronger storyline and with more effective use and interpretation of data. Apply the techniques and guidelines for making data meaningful as given in the UN (United Nations Economic Commission for Europe 2009: Website). publications listed in the reading list in the course guide. A routine statistical story in at least two pages should be reduced effectively to about one page approximately. You are not required to include charts in your improved statistical story.
Portfolio Task 2 -
It seems reasonable to assume that the price of a car is dependent on its age. Decide on a particular type of a car and model (engine, diesel, hybrid, electric etc.) and a suitable source for the data, such as your local newspaper, auto trade magazine etc. Collect data on the age and price of around 30 cars of the same type but of different age. Use Excel or any other statistical software package to do the following:
(a) Plot a scatter graph of the data. Does the scatter graph indicate that a linear relationship exists for all or part of the range of the data?
(b) Obtain the regression equation that would enable the price of the car to be obtained given its age.
(c) Using the equation obtained in (b) above and suitable examples, illustrate how the price of a car could be found if its age was known. Within what age range is your equation valid? Why is this so?
(d) What proportion of the variability in price is explained by the age factor?
(e) Using regression in Excel Tool Pak Add-in or any other statistical software interpret any p-value and explain its use along with the t-test value. What do confidence intervals in the solution tell you?
(f) Investigate whether other factors, such as size of the engine etc, would improve the fit of the regression equation.