Exercise 15.12 Select the best answer for each problem: The scatterplot for the data is A. moderate to strong The strength of the association is B. negative The form of the relationship is C. positive The direction of the association is D. roughly linear Find the least squares line. E. false True or False. We could use our regression line to F. true predict the number of larvae clusters expected for 10 G. 70 stumps. H. y = -1.29x + 11.89 What is the correlation, r, between the variables? I. not linear What percentage of the observed variation in beetle 1. 4 larvae counts can be explained by the straight line relationship with the stump counts? K. y = -1.29 + 11.89x Predict the number of beetle larvae clusters for 6 L. 0.916 stumps. M. 83.9% True or False: Counting stumps gives a quick and N. 91.6% reliable way to predict the number of beetle larvae clusters O. False. 10 stumps is well beyond the range of our original data. This is known as extrapolation, and is not a good idea p. drawn with number of stumps on the y-axis since it is the explanatory variable, and number of larvae clusters on the x- axis since it is the response variable. Q. True. The regression line can be used to make predictions for any number of stumps since the correlation is high