Math Problem Statement
Solution
This problem involves finding a linear regression equation to model the given data set, which describes the value of an investment in dollars, years after 1994.
The table of values provided is:
(years after 1994) | 1 | 3 | 7 | 12 | 14 | 19 |
---|---|---|---|---|---|---|
(value in $) | 12270 | 11573.8 | 10890 | 10032.2 | 9280 | 7723.5 |
To solve:
-
Determine the linear regression equation: This equation will have the form: where:
- is the slope of the regression line (representing the rate of change in value per year).
- is the y-intercept, representing the value of the investment in the year 1994 (when ).
-
Calculate the slope : The slope is calculated as: where and are the means of and , respectively.
-
Find the y-intercept : Once is known, use the equation and substitute one of the known points (e.g., , ) to find .
I will now calculate the slope and the intercept using the given data points to provide the full linear regression equation.The linear regression equation that models the given data is:
Interpretation:
- The slope indicates that the value of the investment decreases by approximately $236.97 per year.
- The y-intercept suggests that the value of the investment in the year 1994 (when ) was approximately $12,506.64.
Let me know if you want further details or explanations.
Here are some related questions you can consider:
- How do we interpret the slope in this context?
- Can linear regression always be used to model investment trends?
- What happens to the investment value 30 years after 1994?
- How would the model change if the trend reversed (increasing instead of decreasing)?
- What is the expected value of the investment in the year 2005?
Tip: When performing regression analysis, always check if a linear model is appropriate by analyzing the residuals.
Ask a new question for Free
By Image
Drop file here or Click Here to upload
Math Problem Analysis
Mathematical Concepts
Linear Regression
Slope-Intercept Form
Algebra
Formulas
Linear regression equation: y = mx + b
Slope formula: m = (Σ(xi - x̄)(yi - ȳ)) / (Σ(xi - x̄)^2)
Intercept formula: b = y - mx
Theorems
Linear Regression Theorem
Suitable Grade Level
Grades 10-12