Exercise 8.26 presents regression output from a model for predicting the heart weight (in g) of cats from their body weight (in kg). The coefficients are estimated using a dataset of 144 domestic cat. The model output is also provided below.

(a) We see that the point estimate for the slope is positive. What are the hypotheses for evaluating whether body weight is positively associated with heart weight in cats?

(b) State the conclusion of the hypothesis test from part (a) in context of the data.

(c) Calculate a 95% confidence interval for the slope of body weight and interpret it in context of the data.

(d) Do your results from the hypothesis test and the confidence interval agree? Explain.

Data from Exercise 8.26 

The following regression output is for predicting the heart weight (in g) of cats from their body weight (in kg). The coefficients are estimated using a dataset of 144 domestic cats.

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(Intercept) body wt Estimate Std. Error t value 0.692 -0.515 0.250 16.119 s = 1.452 -0.357 4.034 R² = 64.66% Pr(>|t|) 0.607 0.000 Radi = 64.41%