# Question

An investigation of the relationship between x = traffic flow (thousands of cars per 24 hours) and y 5 lead content of bark on trees near the highway (mg/g dry weight) yielded the accompanying data. A simple linear regression model was fit, and the resulting estimated regression line was y^ = 28.7 1 33.3x. Both residuals and standardized residuals are also given.

a. Plot the (x, residual) pairs. Does the resulting plot suggest that a simple linear regression model is an appropriate choice? Explain your reasoning.

b. Construct a standardized residual plot. Does the plot differ significantly in general appearance from the plot in Part (a)?

a. Plot the (x, residual) pairs. Does the resulting plot suggest that a simple linear regression model is an appropriate choice? Explain your reasoning.

b. Construct a standardized residual plot. Does the plot differ significantly in general appearance from the plot in Part (a)?

## Answer to relevant Questions

Explain the difference between a confidence interval and a prediction interval. How can a prediction level of 95% be interpreted? Return to the regression of y = milk pH on x 5 milk temperature described in the previous exercise. a. Obtain a 95% prediction interval for a single pH observation to be made when milk temperature = 408C. b. Calculate a 99% ...For the cereal data of the previous exercise, the mean x value is 19.21. Would a 95% confidence interval with x* = 20 or x* = 17 be wider? Explain. Answer the same question for a prediction interval. The accompanying summary quantities for x 5 particulate pollution (mg/m3) and y = luminance (.01 cd/ m2) were calculated from a representative sample of data that appeared in the article “Luminance and Polarization of the ...The article “Photocharge Effects in Dye Sensitized Ag[Br,I] Emulsions at Millisecond Range Exposures” (Photographic Science and Engineering [1981]: 138– 144) gave the accompanying data on x = % light absorption and y = ...Post your question

0