The following estimated regression equation relating sales to inventory investment and advertising expenditures was given. ý - 22 + 15x, + 9x2 The data used to develop the model came from a survey of 10 stores; for those data, SSyy (Total Sum of Squares) - 19,000 and SSR (Regression Sum of Squares) - 14,250. (a) For the estimated regression equation given, compute R2.(Round your answer to two decimal places.) R2 = (b) Compute the adjusted r-square, R2. (Round your answer to two decimal places.) R- (c) Does the model appear to explain a large amount of variability in the data? Explain. (For purposes of this exercise, consider an amount large if it is at least 55%. Round your answer to the nearest integer.) The adjusted coefficient of determination shows that % of the variability has been explained by the two independent variables; thus, we conclude that the model -Select-v explain a large amount variability.

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**Estimated Regression Equation and Analysis**

The following estimated regression equation relates sales to inventory investment and advertising expenditures:

\( \hat{y} = 22 + 15x_1 + 9x_2 \)

The data to develop the model was obtained from a survey of 10 stores. The calculations for those data include:

- SSyy (Total Sum of Squares) = 19,000
- SSR (Regression Sum of Squares) = 14,250

**Tasks:**

(a) **Compute \( R^2 \) for the Estimated Regression Equation**

To calculate \( R^2 \), use the formula:
\[ R^2 = \frac{\text{SSR}}{\text{SSyy}} \]

Round your answer to two decimal places.

**\( R^2 = \_\_\_\_ \)**

(b) **Compute the Adjusted \( R^2 \), \( R^2_a \)**

Use the adjusted \( R^2 \) formula:
\[ R^2_a = 1 - \left(\frac{(1 - R^2)(n - 1)}{n - p - 1}\right) \]

Where \( n \) is the number of observations, and \( p \) is the number of independent variables.

Round your answer to two decimal places.

**\( R^2_a = \_\_\_\_ \)**

(c) **Model Variability Explanation**

Determine if the model explains a large amount of variability.

Consider the variability explanation significant if it is at least 55%. Round your answer to the nearest integer.

**Conclusion:**

The adjusted coefficient of determination shows that \_\_\_\_ % of the variability has been explained by the two independent variables. Therefore, we conclude that the model \_\_\_ explain a large amount of variability.

--- 

This text is designed as an educational guide for understanding and computing the components of a regression analysis, emphasizing practical application and interpretation of \( R^2 \) and adjusted \( R^2 \).
Transcribed Image Text:**Estimated Regression Equation and Analysis** The following estimated regression equation relates sales to inventory investment and advertising expenditures: \( \hat{y} = 22 + 15x_1 + 9x_2 \) The data to develop the model was obtained from a survey of 10 stores. The calculations for those data include: - SSyy (Total Sum of Squares) = 19,000 - SSR (Regression Sum of Squares) = 14,250 **Tasks:** (a) **Compute \( R^2 \) for the Estimated Regression Equation** To calculate \( R^2 \), use the formula: \[ R^2 = \frac{\text{SSR}}{\text{SSyy}} \] Round your answer to two decimal places. **\( R^2 = \_\_\_\_ \)** (b) **Compute the Adjusted \( R^2 \), \( R^2_a \)** Use the adjusted \( R^2 \) formula: \[ R^2_a = 1 - \left(\frac{(1 - R^2)(n - 1)}{n - p - 1}\right) \] Where \( n \) is the number of observations, and \( p \) is the number of independent variables. Round your answer to two decimal places. **\( R^2_a = \_\_\_\_ \)** (c) **Model Variability Explanation** Determine if the model explains a large amount of variability. Consider the variability explanation significant if it is at least 55%. Round your answer to the nearest integer. **Conclusion:** The adjusted coefficient of determination shows that \_\_\_\_ % of the variability has been explained by the two independent variables. Therefore, we conclude that the model \_\_\_ explain a large amount of variability. --- This text is designed as an educational guide for understanding and computing the components of a regression analysis, emphasizing practical application and interpretation of \( R^2 \) and adjusted \( R^2 \).
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