We use the form
for the least-squares line. In some computer printouts, the least-squares equation is not given directly. Instead, the value of the constanta is given, and the coefficientb of the explanatory or predictor variable is displayed. Sometimesa is referred to as the constant, and sometimes as the intercept. Data from a report showed the following relationship between elevation (in thousands of feet) and average number of frost-free days per year in a state.
Notice that "Elevation" is listed under "Predictor." This means that elevation is the explanatory variablex. Its coefficient is the slopeb. "Constant" refers toa in the equation
(b) For each 1000-foot increase in elevation, how many fewer frost-free days are predicted? (Round your answer to three decimal places.)
(c) The printout gives the value of the coefficient of determinationr2. What is the value ofr? Be sure to give the correct sign forr based on the sign ofb. (Round your answer to four decimal places.
(d) What percentage of the variation iny can be explained by the corresponding variation inx and the least-squares line?
What percentage is unexplained?
Already registered? Login
Not Account? Sign up
Enter your email address to reset your password
Back to Login? Click here