2. The Great Plains Railroad is interested in studying how fuel consumption is related to the number of railcars for its trains on a certain route between Oklahoma City and Omaha. A scatterplot and residual plot from the regression analysis for these data are shown below. RESIDUALS VERSUS THE FITTED VALUES 120 110- 100 90+ 80- 70 60아 50 20 30 50 50 60 70 80 90 100 1 io 120 40 Fitted Value Number of Railcars After some calculation, we found that the correlation coefficient is r = 0.9835. Our descriptive statistics also tell us that for the Number of Railcars x, i = 35.6 and s, = 10.42. Alongside this information we also know that for Fuel Consumption y, ỹ = 87.2 and s, = 22.76. a) Using the information above, provide a brief description of the scatterplot. b) Would a linear model be appropriate for modeling these data? Explain your reasoning. c) Interpret the coefficient of determination r2. d) Suppose that s = 4.361. Interpret this value in context. e) Using the information above, construct the equation of its Least-Squares Regression Line. Fuel Consumption Residual

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**Title: Analyzing Fuel Consumption in Relation to Railcar Number**

The Great Plains Railroad is conducting a study on how fuel consumption correlates with the number of railcars on a specific route between Oklahoma City and Omaha. Below are a scatterplot and a residual plot from the regression analysis of these data.

**Data Visualization:**

1. **Scatterplot:**
   - **X-axis:** Number of Railcars.
   - **Y-axis:** Fuel Consumption.
   - The plot displays a positive linear trend, indicating that as the number of railcars increases, fuel consumption also increases.

2. **Residual Plot:**
   - **X-axis:** Fitted Values.
   - **Y-axis:** Residuals.
   - The residuals are scattered randomly around zero, suggesting that the linear model is appropriate for these data.

**Statistical Insights:**

- **Correlation Coefficient:** \( r = 0.9835 \), indicating a very strong positive linear relationship.
- Descriptive statistics for the Number of Railcars:
  - Mean (\( \bar{x} \)) = 35.6
  - Standard Deviation (\( s_x \)) = 10.42
- Descriptive statistics for Fuel Consumption:
  - Mean (\( \bar{y} \)) = 87.2
  - Standard Deviation (\( s_y \)) = 22.76

**Questions and Discussion:**

a) **Scatterplot Description:**
   - The scatterplot displays a strong positive linear relationship between the number of railcars and fuel consumption.

b) **Linear Model Appropriateness:**
   - A linear model appears suitable given the strong correlation coefficient (r = 0.9835) and the random pattern of residuals around zero.

c) **Coefficient of Determination (\( r^2 \)):**
   - Interpret \( r^2 \) as the percentage of variation in fuel consumption explained by the number of railcars. Given the high \( r \), \( r^2 \) is near 0.967, meaning about 96.7% of the variation is explained by the model.

d) **Standard Error Interpretation:**
   - The value \( s = 4.361 \) implies the typical deviation of the observed fuel consumption from the values predicted by the model is approximately 4.361 units.

e) **Equation of Least-Squares Regression Line:**
   - Using the given
Transcribed Image Text:**Title: Analyzing Fuel Consumption in Relation to Railcar Number** The Great Plains Railroad is conducting a study on how fuel consumption correlates with the number of railcars on a specific route between Oklahoma City and Omaha. Below are a scatterplot and a residual plot from the regression analysis of these data. **Data Visualization:** 1. **Scatterplot:** - **X-axis:** Number of Railcars. - **Y-axis:** Fuel Consumption. - The plot displays a positive linear trend, indicating that as the number of railcars increases, fuel consumption also increases. 2. **Residual Plot:** - **X-axis:** Fitted Values. - **Y-axis:** Residuals. - The residuals are scattered randomly around zero, suggesting that the linear model is appropriate for these data. **Statistical Insights:** - **Correlation Coefficient:** \( r = 0.9835 \), indicating a very strong positive linear relationship. - Descriptive statistics for the Number of Railcars: - Mean (\( \bar{x} \)) = 35.6 - Standard Deviation (\( s_x \)) = 10.42 - Descriptive statistics for Fuel Consumption: - Mean (\( \bar{y} \)) = 87.2 - Standard Deviation (\( s_y \)) = 22.76 **Questions and Discussion:** a) **Scatterplot Description:** - The scatterplot displays a strong positive linear relationship between the number of railcars and fuel consumption. b) **Linear Model Appropriateness:** - A linear model appears suitable given the strong correlation coefficient (r = 0.9835) and the random pattern of residuals around zero. c) **Coefficient of Determination (\( r^2 \)):** - Interpret \( r^2 \) as the percentage of variation in fuel consumption explained by the number of railcars. Given the high \( r \), \( r^2 \) is near 0.967, meaning about 96.7% of the variation is explained by the model. d) **Standard Error Interpretation:** - The value \( s = 4.361 \) implies the typical deviation of the observed fuel consumption from the values predicted by the model is approximately 4.361 units. e) **Equation of Least-Squares Regression Line:** - Using the given
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