Tracking hurricanes In Chapter 6, we looked at data from the National Oceanic and

Chapter 26, Problem 11

(choose chapter or problem)

Tracking hurricanes In Chapter 6, we looked at data from the National Oceanic and Atmospheric Administration about their success in predicting hurricane tracks. Below is a scatterplot of the error (in nautical miles) for predicting hurricane locations 24 hours in the future vs. the year in which the prediction (and the hurricane) occurred. In Chapter 6, we could describe this relationship only in general terms. Now we can learn more. Here is the regression analysis: Dependent variable is 24Error R-squared = 68.7% s = 16.44 with 41 - 2 = 39 degrees of freedom Variable Coefficient SE(Coeff) t-Ratio P-Value Intercept 132.3 5.043 26.2 0.0001 Years Since 1970 -2.01 0.217 -9.25 0.0001 a) Explain in words and numbers what the regression says. b) State the hypothesis about the slope (both numerically and in words) that describes how hurricane prediction quality has changed. c) Assuming that the assumptions for inference are satisfied, perform the hypothesis test and state your conclusion. Be sure to state it in terms of prediction errors and years. d) Explain what the R-squared means in terms of this regression.