Stat Assignment

Need to use Geogebra wich you can download  for free.

Math 119 — Lab 2 Name:

Directions: You are required to turn in a print out of your work (not
necessarily a color copy). The due date for this lab is TBD. The data sets
for both case studies (below) are in the same GeoGebra (.ggb) file located on
the course materials webpage, the slide associated with Lab 2. (direct link)
Please use a 20-point font on any graphs you make.

Case Study: In an investigation of environmental causes of disease, data
were collected on the annual mortality rate (deaths per 100,000) for males
in 61 large towns in England and Wales. In addition, the water hardness
was recorded as the calcium concentration (parts per million, ppm) in the
drinking water.

1. Graphing. Export and paste your graphs into your text document.

(a) Make a scatter plot of Calcium (x) versus Mortality rate (y). Copy
this to your graphics view.

(b) Make sure your axes are square, and that your graph has the axes
equally scaled. How to do this:

1. Open your object properties (gear icon) and click on “preferences
graphics.”

2. Set both the values of x-min and y-min to −225.
3. Set the values of x-max and y-max to 2200.

4. Then set “xAxis : yAxis” to be a 1 to 1 ratio.

5. Make visible your coordinate grid.

6. Visually check that the axis looks square.

7. Label your axes; then export your graph to a png file.

(c) Make a residual plot of the data. Set your axis square, label your
axes, turn the grid on and export your figure.

(d) Calculate the statistics of both variables and include a table in your
text document summarizing the statistics. Include the values of r
and r2.

http://timbusken.com/html_pages/math-119/course%20materials.html

2. Analysis. Please use full, coherent sentences to answer the following
questions. Please type your answers into your text document.

(a) Describe what you see in this scatterplot, in context.

(b) Which variable should we take as the response variable? As the
explanatory variable?

(c) What is the regression equation?

(d) Interpret the slope and y-intercept of the line, in context. Be specific.

(e) What is the value of the largest residual? (Recall that a residual is
the difference between the observed and predicted values.) Explain
what this means.

(f) The hardness of Derby’s municipal water is about 100 ppm. Use the
regression equation to predict the mortality rate in Derby.

(g) Explain the meaning of r2 in this context.

Case Study: A very difficult exam was administered to 37 math, science
and engineering students. The exam scores given in the same ggb (geogebra)
file as the previous case study.

3. Graphing and Analysis. Export and paste your graphs into your word
document. Label your axes in each figure for full credit.

(a) Make a histogram of the test scores with 9 classes (bars) from 10 to
100, using a class width of 10. Note: your axes do not have to be
square for this figure.

(b) Make a distribution table of the test scores.

(c) Make a table summarizing the exam statistics.

Sheet1

02

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0

9

39393

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93.9393939394

27

9.3939393939

.0

9090909

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5757576

75

1

13

.4848484848

14

21212121

8

.9393939394

14

68

75

71

.6060606061

13

57

71

60

1486

71

21 40.1515151515

14

.5

1625 13

17

5

00

14

18

10

15

78

10

84

73

12

78

96

20

39

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122

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21

44

94

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91

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37

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8

26

																																																																												mortality	calcium	Test scores
	17		44			10
			13	9			5		93.9		39	94
	12	133
				14	27				8
1724		6	86.3636363636
11		75	107		84	90
	1486	83.3333333333
1456	79.5454545455
	16	96	75.7	57
1236	101
1			71		73
1444	71.		21
		15	91	49	70.0757575758
1987		68
1495	66.6666666667
1369	65.9090909091
1257	50	64.3939393939
1587	62.1212121212
1713		60
1557	59.8484848485
1640	59.4696969697
1709	58.7121212121
	1625		20	55.303030303
1527	52.6515151515
1627	53	51.1363636364
	122	49.2424242424
1485	81	46.5909090909
13		78		40.1515151515
1519
1581		37
34.8484848485
1247	105	31.0606060606
1668	29.1666666667
1466	27.2727272727
	18	24.2424242424
1609	21.9696969697
1558	16.2878787879
1807
1299
1637
1359
1392
1755
1307
1254
1491
1555
1428
1318
1	26
1723
1379
1742
1574
1569
1096	138
1591
1402
1772
1828
1704

Sheet2

Sheet3