Math Problem Statement
Consider the following variables for X and y X / y 2 / 4 3 / 5 4 / 4 5 / 6 7 / 4 7 / 6 7 / 9 8 / 5 9 / 11 Perform a logarithmic transformation on the dependent variable y. Develop an estimated regression equation using the transformed dependent variable
Solution
To perform a logarithmic transformation on the dependent variable , we need to take the natural logarithm (ln) of each value, then develop a linear regression equation using as the independent variable and as the dependent variable.
Step 1: Logarithmic Transformation of
We compute for each value of :
X & y & \ln(y) \\ \hline 2 & 4 & \ln(4) \approx 1.386 \\ 3 & 5 & \ln(5) \approx 1.609 \\ 4 & 4 & \ln(4) \approx 1.386 \\ 5 & 6 & \ln(6) \approx 1.792 \\ 7 & 4 & \ln(4) \approx 1.386 \\ 7 & 6 & \ln(6) \approx 1.792 \\ 7 & 9 & \ln(9) \approx 2.197 \\ 8 & 5 & \ln(5) \approx 1.609 \\ 9 & 11 & \ln(11) \approx 2.398 \\ \end{array}$$ ### Step 2: Perform Linear Regression Now, we need to estimate a linear regression model of the form: $$\ln(y) = a + bX$$ Using the data points $$X$$ and $$\ln(y)$$, we can compute the coefficients $$a$$ (intercept) and $$b$$ (slope) using the least-squares method. Let me calculate the regression coefficients for you.The estimated regression equation after performing the logarithmic transformation on $$y$$ is: $$\ln(y) = 1.182 + 0.095X$$ This equation represents the relationship between $$X$$ and the natural logarithm of $$y$$, where the intercept is approximately 1.182 and the slope is 0.095. Would you like more details on this process or have any questions? Here are 5 related questions to deepen understanding: 1. How does a logarithmic transformation help in regression analysis? 2. What are the assumptions of linear regression? 3. How can we interpret the slope and intercept in this transformed model? 4. Can you revert the logarithmic transformation to predict actual $$y$$ values? 5. What are the advantages of transforming the dependent variable in non-linear data? **Tip:** When interpreting coefficients in a log-transformed model, a one-unit increase in $$X$$ corresponds to approximately a percentage change in $$y$$, not a simple linear increase.Ask a new question for Free
By Image
Drop file here or Click Here to upload
Math Problem Analysis
Mathematical Concepts
Logarithmic Transformation
Linear Regression
Natural Logarithm
Formulas
ln(y) = a + bX
Natural logarithm: ln(y)
Least squares method
Theorems
Linear Regression Theorem
Suitable Grade Level
College level
Related Recommendation
Finding a Logarithmic Equation from Data: y = e^(-0.074x + 0.463)
Logarithmic Transformation of Exponential Model y = a * b^x to Fit Linear Regression
Logarithmic Regression Equation and Estimation Example
Linearizing the Exponential Equation y = -Ae^(-Cx) + B
Linearization of Equation O - 75.15 = K y^n