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Course Documents

Chapter 1 - Intro

Chapter 2 - Methods for Describing Sets of Data

Chapter 3 - Probability

Chapter 4 - Discrete Random Variables

Chapter 5 - Normal Random Variables

Chapter 6 - Sampling Distributions

Chapter 7 - Confidence Intervals

Chapter 8 - Tests of Hypothesis: One Sample

Chapter 9 - Confidence Intervals and Hypothesis Tests: Two Samples

Sample Exam I: Chapters 1 & 2

Sample Exam II: Chapters 3 & 4

Sample Exam III: Chapters 5 & 6

Sample Exam IV: Chapters 7 & 8

Example 171tech

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.

Model Summary

      S    R-sq  R-sq(adj)  
32.5974  52.18%     50.92%     


Coefficients

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?

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