Question 1, Reference librarians

Chi Square, question 1

         
 

AZ

UT

Illinois

row totals

N

High

35

24

32

91

 

Low

15

66

28

109

 

Col totals

50

90

60

200

200

           

Fe

22.75

40.95

27.3

   
 

27.25

49.05

32.7

   
           

fo-fe

12.25

-16.95

4.7

   
 

-12.25

16.95

-4.7

   
           

squares

150.0625

287.3025

22.09

   
 

150.0625

287.3025

22.09

   
           

/fe

6.596153

7.015934

0.809157

   
 

5.506880

5.857339

0.675535

   
           

chi sq =

26.46100

       

chi crit(0.05)2 =

5.99

       
 

chiobs>chicrit, reject null

       

 

 

Correlation Problem, Question 2

 Exp p/c

%college grads 

XY

10.65

12.2

129.93

29.49

21.1

622.239

16.13

17.4

280.662

7.85

10.8

84.78

17.46

19.6

342.216

21.23

23

488.29

28.56

20.7

591.192

11.39

17.5

199.325

34.45

27.5

947.375

15.85

14.9

236.165

13.09

14.6

191.114

16.16

20.3

328.048

15.08

15.8

238.264

25.85

16.2

418.77

26.76

12.5

334.5

16.55

13.9

230.045

21.2

17

360.4

10.22

11.1

113.442

13.61

13.9

189.179

16.73

14.4

240.912

23.29

20.4

475.116

21.52

20

430.4

17.66

14.3

252.538

22.61

17.4

393.414

7.94

12.3

97.662

17.23

13.9

239.497

11.14

17.5

194.95

17.26

15.5

267.53

18.67

14.4

268.848

19.62

18.2

357.084

29.73

18.3

544.059

16.18

17.6

284.768

31.66

17.9

566.714

13.38

13.2

176.616

13.85

14.8

204.98

30.48

13.7

417.576

12.73

15.1

192.223

19.96

17.9

357.284

13.86

13.6

188.496

20.46

15.4

315.084

11.52

13.4

154.368

15.85

14

221.9

10.19

12.6

128.394

11.2

16.9

189.28

16.99

19.9

338.101

15.49

19

294.31

19.13

19.1

365.383

25.57

19

485.83

9.39

10.4

97.656

20.97

14.8

310.356

21.88

17.2

376.336

XbarX=18.15

XbarY =16.31

S XY=15753.6

STDX=6.43

STDY =3.31

 

Xbar*Ybar= 

296.03 

 

STDX * STDy=

21.28

 

 

Plug into formula and r =

0.598853 

0.598853

Same number using the CORREL function

 


3. Probability problems

 

 

 

 

 

Event A

 

 

s=17

t= 49

p=0.347

 

 

 

Event B

 

 

s= 326

t = 1009

p=0.324

 

 

 

p (A or B)

 

 

p(A)+p(B)

0.347+0.324 =

p=0.67

 

 

 

p(A and B)

 

 

p(A)*p(B)

0.347*0.324=

p=0.112

 

 

 


 

Academic Library Problem

 

GPA>3.5

GPA<3.5

row total

BI

20

10

30

No BI

15

15

30

col total

35

25

N=60

 

 

 

 

 

 

 

 

Expecteds

17.5

12.5

 

 

17.5

12.5

 

 

 

 

 

Fo-Fe

2.5

-2.5

 

 

-2.5

2.5

 

 

 

 

 

squared

6.25

6.25

 

 

6.25

6.25

 

 

 

 

 

/fe

0.357143

0.5

 

 

0.357143

0.5

 

 

 

 

 

chisq=

1.714286

 

 

Chicrit (0.05)1 =

3.84

 

 

 

chisq obs < chicrit, fail to reject null

 

 

 

 

 

 

Question 5: True!

 

 

 

 

 

Last Updated on 8/9/97
By the prof