In: Statistics and Probability
Use the output below to answer the following questions regarding the association between carbon dioxide levels and amount of coal used.
Estimate Std. Error. t value. P r(> |t|
Intercept 6.166678. 2.171695. 2.84 0.00571
Coal 0.030171. 0.002976 10.14. 4.52e-16
-Create a 98% estimate for the independent variable.
- Is the explanatory variable significant at α = 0.01? -
Suppose the correlation is 0.7478824. Determine the value of the coefficient of determination and explain what this value represents.
- What is the response variable when the explanatory variable is 700? (NOTE: This value is within the range of the explanatory variable)
-Create a 98% estimate for the independent variable
Critical t- score for 98% confidence is t = 2.4033
Lower limit of the confidence interval = b - t * SE = 0.030171 - 2.4033 * 0.002976 = 0.0230
Upper limit of the confidence interval = b + t * SE = 0.030171 + 2.4033 * 0.002976 = 0.0373
The 98% confidence interval for the slope is [0.0230, 0.0373]
- Is the explanatory variable significant at α = 0.01?
p- value (4.52e-16) < α (0.01), so the explanatory variable is significant
- Suppose the correlation is 0.7478824. Determine the value of the coefficient of determination and explain what this value represents
r^2 = 0.7478824^2 = 0.5593. This means about 55.93% of the variation in y is explained by the variation in x using this model
- What is the response variable when the explanatory variable is 700?
When x = 700, y = 0.030171 * 700 + 6.166678 = 27.286378
[Please give me a Thumbs Up if you are satisfied with my answer. If you are not, please comment on it, so I can edit the answer. Thanks.]