Math Problem Statement
The following is the data obtained in the study of the number of absences and the final grade of the seven students in the mathematics class. Construct a scatter diagram for these data.
Calculate the correlation of coefficient (r). Interpret the results.
Find the regression equation.
Plot a regression line on the scatter diagram of part (a).
Predict the final grade with 10 number of absences.
Solution
Analysis:
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Scatter Diagram: The scatter diagram of absences vs. final grades shows a negative correlation, where an increase in the number of absences tends to result in lower final grades.
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Correlation Coefficient (): The calculated correlation coefficient is approximately , indicating a strong negative linear relationship between the number of absences and the final grade. This means that as the number of absences increases, the final grade tends to decrease significantly.
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Regression Equation: The equation for the line of best fit (regression line) is given by: Here, represents the final grade, and represents the number of absences. The negative slope confirms that the grades decrease as absences increase.
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Regression Line Plot: The regression line plotted on the scatter diagram visually represents the downward trend of final grades with increasing absences.
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Prediction for 10 Absences: Using the regression equation, the predicted final grade for a student with 10 absences is approximately .
Would you like more details or have any further questions?
Related Questions:
- How can we interpret the slope of the regression equation in this context?
- What is the coefficient of determination (), and what does it indicate about the data?
- Can we infer causation from the correlation coefficient in this case? Why or why not?
- How would adding more students to this study potentially affect the correlation coefficient?
- What other factors might influence a student's final grade besides the number of absences?
Tip:
When interpreting a correlation coefficient, remember that correlation does not imply causation. Even with a strong correlation, it’s important to consider other potential factors that may influence the relationship between variables.
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Math Problem Analysis
Mathematical Concepts
Statistics
Correlation
Regression Analysis
Prediction
Formulas
Correlation coefficient formula
Linear regression equation y = mx + b
Theorems
Least squares method for linear regression
Suitable Grade Level
High School
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