Question 145214
15.18 Sixty-four students in an introductory college economics class were asked how many credits they had earned in college, and how certain they were about their choice of major. 
Research question: At α = .01, is the degree of certainty independent of credits earned? Certainty 
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Ho: certainty and credits are independent
Ha: they are dependent
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Credits Earned Very Uncertain Somewhat Certain Very Certain Row Total 
0–9 12 8 3 23 
10–59 8 4 10 22 
60 or more 1 7 11 19 
Col Total 21 19 24 64
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I ran a Chi-Sq Test on the 3 x 3 data set  to get:
Chi-Sq = 14.7638...
p-value = 0.00522...
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Conclusion: Since P-value is less than 1%, Reject Ho.
Certainty and credits are dependent
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15.22 A student team examined parked cars in four different suburban shopping malls. One hundred vehicles were examined in each location.
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Research question: At α = .05, does vehicle type vary by mall location? 
(Data are from a project by MBA students Steve Bennett, Alicia Morais, Steve 
Olson, and Greg Corda.) Vehicles 

Vehicle Type Somerset Oakland Great Lakes Jamestown Row Total 
Car 44 49 36 64 193 
Minivan 21 15 18 13 67 
Full-sized Van 2 3 3 2 10 
SUV 19 27 26 12 84 
Truck 14 6 17 9 46 
Col Total 100 100 100 100 400 
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Ho: parking and vehicle type are independent
Ha: they are dependent
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I ran a Chi-Sq Test on the 5x4 set of data with a TI calculator and 
got the following:
Chi-Sq = 24.53154...
p-value = 0.017201..
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Conclusion: Since p-value is less than 5%, reject Ho.
parking place and vehicle type are dependent 
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Cheers,
Stan H.