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1. A recent baseball IQ test was given to 250 random Connecticut baseball fans.

ID: 3364435 • Letter: 1

Question

1. A recent baseball IQ test was given to 250 random Connecticut baseball fans. The scores were classified as Low (little or no baseball knowledge), Intermediate (moderate baseball knowledge) and High (substantial baseball knowledge). Subjects also indicated their favorite baseball team (Mets, Red Sox or Yankees). The results are given in the table below. (Note that since all cells had to have a minimum of 5 to use the test, the last cell had to be augmented by 3)

a. Test the claim that IQ score classification and Favorite team are associated. Be sure to state the null and alternative hypotheses, the test statistic, p-value, and conclusion in plain English. Include the table of expected frequencies.

b. Find the probabilities that a fan scored High given he/she was a fan of each team. (There are 3 probabilities to calculate here).

c. Find the probabilities that a fan scored Low given he/she was a fan of each team. (There are 3 probabilities to calculate here).

d. Write one or two sentences summarizing your findings.

Round answers to the thousandths place.

Score Intermediate 12 48 13 High 38 Low Team Mets Red Sox Yankees 20 85 5

Explanation / Answer

Result:

Ho: there is no association between IQ score classification and Favorite team

H1: there is a association between IQ score classification and Favorite team

test statistic= 139.410

p-value= 0.0000

since P value < 0.05, Ho is rejected.

We conclude that there is association between IQ score classification and Favorite team.

Chi-Square Test

Observed Frequencies

Column variable

Calculations

Row variable

C1

C2

C3

Total

fo-fe

R1

7

12

38

57

-18.5360

-4.6440

23.1800

R2

20

48

22

90

-20.3200

21.7200

-1.4000

R3

85

13

5

103

38.8560

-17.0760

-21.7800

Total

112

73

65

250

Expected Frequencies

Column variable

Row variable

C1

C2

C3

Total

(fo-fe)^2/fe

R1

25.536

16.644

14.82

57

13.4549

1.2958

36.2559

R2

40.32

26.28

23.4

90

10.2406

17.9512

0.0838

R3

46.144

30.076

26.78

103

32.7191

9.6951

17.7135

Total

112

73

65

250

Data

Level of Significance

0.05

Number of Rows

3

Number of Columns

3

Degrees of Freedom

4

Results

Critical Value

9.488

Chi-Square Test Statistic

139.4099

p-Value

0.0000

Reject the null hypothesis

mets

0.667

Red sox

0.244

yankees

0.049

mets

0.123

Red sox

0.222

yankees

0.825

d. Write one or two sentences summarizing your findings.

We conclude that there is association between IQ score classification and Favorite team.

Probabilities that a fan scored high given he/she was a fan of mets team is 0.667.

Probabilities that a fan scored Low given he/she was a fan of yankees team is 0.825

Chi-Square Test

Observed Frequencies

Column variable

Calculations

Row variable

C1

C2

C3

Total

fo-fe

R1

7

12

38

57

-18.5360

-4.6440

23.1800

R2

20

48

22

90

-20.3200

21.7200

-1.4000

R3

85

13

5

103

38.8560

-17.0760

-21.7800

Total

112

73

65

250

Expected Frequencies

Column variable

Row variable

C1

C2

C3

Total

(fo-fe)^2/fe

R1

25.536

16.644

14.82

57

13.4549

1.2958

36.2559

R2

40.32

26.28

23.4

90

10.2406

17.9512

0.0838

R3

46.144

30.076

26.78

103

32.7191

9.6951

17.7135

Total

112

73

65

250

Data

Level of Significance

0.05

Number of Rows

3

Number of Columns

3

Degrees of Freedom

4

Results

Critical Value

9.488

Chi-Square Test Statistic

139.4099

p-Value

0.0000

Reject the null hypothesis