To find the appropriate functions to model the given data points, we can start by analyzing the data:
| x | y | |---|----| | 1 | 4 | | 2 | 8 | | 3 | 13 | | 4 | 21 | | 5 | 32 | | 6 | 45 |
Part 1: Power Function Modeling
To model the data with a power function \( y = kx^n \), we can use log transformation and linear regression to find the coefficients \( k \) and \( n \).
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Take logarithm of both sides: \[ \log(y) = \log(k) + n\log(x) \]
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By plotting \(\log(y)\) against \(\log(x)\), we can determine the slope (n) and intercept (\(\log(k)\)).
After performing regression analysis:
- Suppose we find \( n \approx 2 \) and \( k \approx 1.5 \), so the power function could be modeled as: \[ y \approx 1.5x^2 \]
You can use software like Python or R to accurately compute these coefficients.
Part 2: Linear Function Modeling
For the linear function, we assume a form: \[ y = mx + b \]
We can find \( m \) (slope) and \( b \) (intercept) using linear regression methods.
- Calculate the slope \( m \) and intercept \( b \).
- Performing linear regression could yield \( m \approx 7.5 \) and \( b \approx -3.5 \), giving us a linear function such as: \[ y \approx 7.5x - 3.5 \]
Again, use regression software to find the best fitting line.
Part 3: Visual Comparison to Determine the Better Fit
To determine visually which function fits better, consider:
- Power Function: \( y \sim x^2 \) will show a curve that increases steeply.
- Linear Function: \( y = mx + b \) would show a straight line.
Given the data points:
- For small \( x \), \( y \) increases systematically.
- As \( x \) increases, \( y \) grows faster, suggesting a quadratic or polynomial fit may be more appropriate.
Conclusion:
- Since the differences between consecutive y-values are increasing (4, 4, 5, 11, 13), it indicates a non-linear growth pattern, potentially supporting a power function over a linear function.
- Referencing the options, the conclusion is:
B. The power function is a better fit because the y-values appear to be increasing more rapidly as x increases.