The article cited in Exercise 49 of Chapter 7 gave summary information on a regression in which the dependent variable was power output (W) in a simulated 200-m race and the predictors were x1 = arm girth (cm), x2 = excess post-exercise oxygen consumption (ml/kg), and x3 = immediate posttest lactate (mmol/L). The estimated regression equation was reported as
y = 2408.20 + 14.06x1 + .76x2 - 3.64x3
a. Carry out the model utility test using a significance level of .01.
b. Interpret the estimate 14.06.
c. Predict power output when arm girth is 36 cm, excess oxygen consumption is 120 ml/kg, and lactate is 10.0.
d. Calculate a point estimate for true average power output when values of the predictors are as given in (c).
e. Obtain a point estimate for the true average change in power output associated with a 1 mmol/L increase in lactate while arm girth and oxygen consumption remain fixed.