When a stone is dropped in a pond, ripples form and travel in concentric circles. The relationship between the time and area of the circles is shown in the regression analysis below:

| Predictor | Coef | SE Coef | t | P |
|-----------|------|---------|---|---|
| Constant | 0.490 | 0.00107 | 288.235 | 0.000 |
| Log(Time) | 2.004 | 0.00317 | 633.105 | 0.000 |

R-Sq = 0.999, R-Sq(adj) = 0.999

What is the equation of the least-squares regression line?

A. [tex]\(\widehat{\text{Area}} = 2.004 + 0.490 \log(\text{Time})\)[/tex]

B. [tex]\(\widetilde{\text{Time}} = 0.490 + 2.004 \log(\text{Area})\)[/tex]

C. [tex]\(\log(\widetilde{\text{Area}}) = 2.004 + 0.490 \log(\text{Time})\)[/tex]

D. [tex]\(\log(\text{Area}) = 0.490 + 2.004 \log(\text{Time})\)[/tex]



Answer :

To determine the equation of the least-squares regression line based on the given statistical analysis from the regression output, let's follow these steps:

1. Identify the Dependent and Independent Variables:
- The dependent variable (y) is typically represented as the variable being predicted or explained. In this case, it is [tex]\(\log(\text{Area})\)[/tex].
- The independent variable (x) is the predictor or explanatory variable. In this case, it is [tex]\(\log(\text{Time})\)[/tex].

2. Extract Key Coefficients from the Regression Output:
- The constant term (intercept) is given as 0.490.
- The coefficient for [tex]\(\log(\text{Time})\)[/tex] (slope) is given as 2.004.

3. Formulate the Regression Equation:
- The general form of a linear regression equation is:
[tex]\[ \hat{y} = b_0 + b_1 x \][/tex]
where [tex]\( \hat{y} \)[/tex] is the predicted value, [tex]\( b_0 \)[/tex] is the intercept, and [tex]\( b_1 \)[/tex] is the slope.

4. Substitute the Given Values:
- Here, [tex]\( y = \log(\text{Area}) \)[/tex]
- [tex]\( x = \log(\text{Time}) \)[/tex]
- [tex]\( b_0 = 0.490 \)[/tex]
- [tex]\( b_1 = 2.004 \)[/tex]

Therefore, the equation becomes:
[tex]\[ \log(\text{Area}) = 0.490 + 2.004 \log(\text{Time}) \][/tex]

This detailed step-by-step analysis leads us to the equation of the least-squares regression line. Hence, the correct equation is:
[tex]\[ \log(\text{Area}) = 0.490 + 2.004 \log(\text{Time}) \][/tex]