Math 1020, Mathematics for the Liberal Arts, Fall 2015

Activity #1, Friday, August 28th

Learning Outcomes (continued from Activity 0):

• Converting a “qualitative” scale to numerical

• Expressing a numerical process in one’s own words, based on a written description

• Reading and interpreting graphical summaries of data

• Computing arithmetical mean from graphical data and interpreting the result in context

Names______

Question 1. The Nine Mile Creek Watershed District employs a five-category classification structure for the “ecological use” of a stream (in this case, Nine Mile Creek). (These are the five categories you listed in Activity 0.) Explain how we can think of this classification as quantitative (i.e. numerical), even though it uses letters. What is it that’s being “measured?” Use the actual names of the five classes in your answer, not just the “letter values” assigned to them.

Question 2. Explain in your own words how we find the existing ecological use of a stream reach. Emphasize how numbers and mathematics are involved.

Question 3. Explain in your own words how we find the historical ecological use of a stream reach. Emphasize how numbers and mathematics are involved.

Looking at the graphs of historical ecological uses:

Question 4. What quantity/variable is measured on the horizontal (“x”) axis?

Question 5. What quantity/variable is measured on the vertical (“y”) axis?

Question 6. Wait, WHAT?!? What were our five classifications for ecological use? How did these get turned into a numerical scale?

OK, looking at the graphs:

Question 7. About what range of numerical values (from the “y” axis) correspond to class E?

Question 8. About what range of numerical values (from the “y” axis) correspond to class D?

Question 9. About what range of numerical values (from the “y” axis) correspond to class C?

Question 10. About what range of numerical values (from the “y” axis) correspond to class B?

Question 11. About what range of numerical values (from the “y” axis) correspond to class A?

Question 12. If you were to guess, based on the graphs, what specific numerical value is being assigned to each ecological use category? (Fill in the table below with your best guesses. Use whole numbers.)

A / B / C / D / E

Question 13. Let’s do a sample calculation. Look at the graph labeled EUC-13, which gives existing ecological uses for reach 5A of the south fork. First, fill in the following table with the data shown in the graph. Approximate ecological use values as best you can from the graph; give one decimal place:

Time
Ecological Use

Question 14. Based on your table, calculate the historical ecological use of Reach 5A for the time period Oct. 1997 – July 2003:

Question 15. What is the corresponding “letter grade” for this numerical classification? Does this classification seem to match the overall trend displayed in the graph? Explain.

Discussion break: Figure EUC-16, reach 7C.