Question 617184: A statistic professor conducts a study to investigate the relationship between the performance of his students on exams and their anxiety. Ten students from his class are selected for the experiment. Just before taking the final exam, the 10 students are given an anxiety questionnaire. Final scores are:
students No anxiety final exam
1 28 82
2 41 35
3 35 63
4 39 89
5 31 92
6 42 64
7 50 55
8 46 70
9 45 51
10 37 72
(a) construct a scatter plot of the paired scores. use anxiety as the X variable.
b. describe the relationship shown in the graph
c. Assuming the relationship is linear, compute the value of Pearson r.
d. determine the least-squares regression line for predicting the final exam score, given the anxiety level. should b(y) be positive or negative? why?
e. draw the least-squares regression line of part (d) on the scatter plot of part (a)
f. based on the data of the 10 students, if a student has an anxiety score of 38, what value would you predict for her final exam score? round to two decimals.
g. calculate the standard error of estimate for predicting for her final scores from anxiety scores. clinical, health, education
Answer by Theo(13342)   (Show Source):
You can put this solution on YOUR website! (a) construct a scatter plot of the paired scores. use anxiety as the X variable.
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GRAPH FOR CORRELATION STUDY
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b. describe the relationship shown in the graph
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fairly scattered distribution with a general downward trend indicating that the higher anxiety level of the student corresponds with a generally lower score on the test.
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c. Assuming the relationship is linear, compute the value of Pearson r.
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R = -.5870264049
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d. determine the least-squares regression line for predicting the final exam score, given the anxiety level. should b(y) be positive or negative? why?
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y = -1.5156x + 127.02
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e. draw the least-squares regression line of part (d) on the scatter plot of part (a)
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see the graph.
the regression line is already there.
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f. based on the data of the 10 students, if a student has an anxiety score of 38, what value would you predict for her final exam score? round to two decimals.
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an anxiety level of 38 predicts a score of about 69.
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g. calculate the standard error of estimate for predicting for her final scores from anxiety scores. clinical, health, education
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standard error of estimate is equal to 15.18962
EXCEL WORKSHEET SHOWING STATISTICAL MEASURES FOR CORRELATION STUDY
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reference:
http://www.okstate.edu/ag/agedcm4h/academic/aged5980a/5980/newpage24.htm
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