Assignment 3 Questions

1. The table at the bottom shows the population of Oregon counties from 1950 to 2010. You have just been giving a job as resource manager for the state of Oregon, and you need to examine the population base as a function of county within the state. This is your first day on the job and your boss gives you a bunch of data to distill to answer the following questions:
   
   

    

   
   

   a)	What is the fastest growing county (in terms of percentage not raw population) in Oregon since 1990?
   b)	Using the exponential growth tool and the information in the table below determine the average growth rates from 1970-2010 for the following counties: Jackson, Lane, Marion, Multnomah and Washington. To use the growth tool, simply enter in the years in the X-axis and the population in the Y-Axis and then guess an initial growth rate - adjust the growth rate until you think you get the best fitting line. The slope of that line is the growth rate in units of % per decade.
   c)	Compare the growth rates from 1970 to 1980 with those from 1980 to 1990 for Lane county. What do you see and do you have an explanation for this result

    d) Now determine the growth rate for Lane County from 1990-2010 and predict the population for Lane County in the year 2025. Comment on the accuracy of this prediction.

   e) now just from looking at the numbers in the table - if you were using the rate of population change from 1950 - 1970 to predict the 2010 county population, which county would be the most off from this prediction.  Explain your choice.

    

   
   
   

    

   Historical Population of Oregon Counties
   In units of thousands of people
   

   County	2010	2000	1990	1980	1970	1960	1950
   Baker	16.4	16.7	15.3	16.1	14.9	17.3	16.2
   Benton	87	78.1	70.8	68.2	53.8	39.2	31.5
   Clackamas	382	339	278	242	166	113	87
   Clatsop	37.8	35.6	33.3	32.5	28.5	27.4	30.8
   Columbia	48.6	43.6	37.6	35.6	28.8	22.4	23.0
   Coos	63.0	62.7	60.3	64.0	56.5	55.9	42.7
   Crook	27.3	19.4	14.1	13.1	10.0	9.4	9.0
   Curry	21.1	21.1	19.3	17.0	13.0	14.0	6.0
   Deschutes	172	117	75	62	30	23	22
   Douglas	105	100	95	94	72	68	55
   Gilliam	1.9	1.9	1.7	2.1	2.3	3.1	2.8
   Grant	7.6	7.9	7.8	8.2	7.0	7.7	8.3
   Harney	7.7	7.6	7.1	8.3	7.2	6.7	6.1
   Hood River	21.5	20.5	16.9	15.8	13.2	13.4	12.7
   Jackson	208	182	146	132	95	74	59
   Jefferson	22.8	19.1	13.7	11.6	8.5	7.1	5.5
   Josephine	83.6	76	63	59	36	30	26
   Klamath	66.5	64	58	59	50	47	42
   Lake	7.6	7.4	7.2	7.5	6.3	7.2	6.6
   Lane	349	323	284	275	213	163	126
   Lincoln	44.6	44.3	38.9	35.3	25.8	24.6	21.3
   Linn	111	103	91	89	72	59	54
   Malheur	31.6	31.5	26.0	26.9	23.2	22.7	23.2
   Marion	321	285	228	205	151	121	101
   Morrow	12.3	11.1	7.6	7.5	4.4	4.8	4.8
   Multnomah	730	661	584	563	557	522	472
   Polk	69.1	62	50	45	35	27	26
   Sherman	1.8	1.9	1.9	2.2	2.1	2.4	2.3
   Tillamook	26.1	24.2	21.6	21.1	17.9	18.9	18.6
   Umatilla	72	71	59	59	45	44	42
   Union	25.2	24.5	23.6	23.9	19.4	18.2	17.9
   Wallowa	7.1	7.2	6.9	7.3	6.3	7.1	7.3
   Wasco	24.1	23.8	21.7	21.7	20.1	20.2	15.6
   Washington	533	448	311	246	158	92	61
   Wheeler	1.6	1.5	1.4	1.5	1.8	2.7	3.3
   Yamhill	96	85	65	55	40	32	33

    

2. There are currently 400 parts per million of CO₂ in our atmosphere.  Averaged over the last 10 years the annual growth rate of CO₂ is 0.8% per year.  

• a) at this growth rate what will the concentration of CO₂ be in the year 2100;

• b) if we and China just burn up our coal until 2100 the growth rate will increase to 1.2% - under these conditions what will the concentration be in the year 2100;

• c) Climate models suggest that for every 150 ppm increase the global mean temperature will rise by 2 degrees C:  Any values larger than +5 C from current values are considered dangerous.  Under the two growth scenarios above, in what year will we pass these thresholds.

3. Get the Data for this question here (note you can download it into excel from this site)

During June 2008, gas prices reached an all time high of about $4.50 a gallon. At that price, newspaper headlines were proclaiming "High Gas Prices Force Consumers to Drive Significantly Less". Well, you have the raw data and can now use it to answer a bunch of questions with the data, rather than making up stories for the media.

Using the data, answer the following parts:

a) Typically summer time driving dominates seasonal driving patterns. Determine the average weekly consumption from June through September in the years 2005--2007. Now determine the average for 2008 - 2009. What precentage reduction is there in the 2008-2009 period with that in 2005--2007?

b) Now derive the average weekly consumptino from June 2011 through Sept 2011. Compare that to the 2008--2009 time period.

C) Now let's use Week 3 in July as our standard. Using resources such as gasbuddy.com plot that standard from 2000-2011 as a function of the average price of gasoline for that year.

d) From your graph, predict what the week 3 July consumption will be if gas rises to 6$ per gallon.

e) Now you have done a data driven exercise. Write a short, 200 word, newspaper style article on the driving habits of Americans as a function of the price of gas.