Correlation and Regression Analysis
Question2ﾃつﾃつﾃつﾃつﾃつﾃつﾃつﾃつﾃつﾃつﾃつﾃつﾃつﾃつﾃつﾃつﾃつ
The marks in a Physics exam (P) and a Chemistry exam (C) wererecorded for 15 students:
Physics | 25 | 46 | 63 | 45 | 78 | 18 | 84 | 48 | 73 | 50 | 61 | 89 | 38 | 36 | 30 |
Chemistry | 31 | 44 | 58 | 49 | 66 | 12 | 61 | 56 | 70 | 57 | 62 | 56 | 29 | 40 | 38 |
- Draw a scatter diagram and comment.
- Find the regression line where the Chemistry mark is theexplanatory variable and the Physics mark is the responsevariable.
- Calculate the correlation between P and C. Test the hypothesis,at 5%, that it is positive.
- Predict the Physics mark of three students, one obtaining 20 inChemistry, one 50 in Chemistry and the third 80 in Chemistry. Whichof the three predictions do you trust more?
- Perform a hypothesis test that the slope of the regression lineis positive.
