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Example 171 tech: A study looked at the relationship between the number of hours spent sitting each day and the LDL cholesterol number for each participant. The study, which used a prospective cohort study design, followed 40 participants for ten years. At the start of the study, all participants had similar LDL numbers but varied with respect to the number of hours they spent being sedentary. The results of the analysis are given below. Use the results to answer the questions that follow.
S R-sq R-sq(adj)
32.5974 52.18% 50.92%
Term Coef SE Coef T-Value P-Value
Constant -23.4 20.5 -1.14 0.261
No.Sedentary hrs 14.00 2.17 6.44 0.000
Regression Equation: LDL = -23.4 + 14.00 * (No.Sedentary hrs)
a) Is there a significant linear relationship between these variables? If so, is the correlation positive or negative?
b) Interpret the coefficient of determination, r²
c) Find and interpret the correlation coefficient, r.
d) Interpret the slope of the provided regression equation.
e) Do these results imply that being sedentary causes higher LDL levels?