## Fall 2014: HS 550

#### Homework 3

Using the SOCR Clinical, Genetic and Imaging Data of Alzheimer’s Disease:
• Problem 1: Assess if there are significant differences between the MMSE scores of the two groups of patients defined by Group0 ={GDTOTAL=0} and Group1={GDTOTAL=1}.
• Problem 2: Compare the proportions of patients with {GDTOTAL > 0} in these two groups Group3={CDGLOBAL=1} vs. Group4={CDGLOBAL=0}.
• Problem 3: Compare the groups of MCI-to-AD converters (DX_Conversion) in terms of their MMSCORE scores.
• Problem 4: Test a null hypothesis that the standard deviation of the MMSCORE variable is equal to σo=2.5.
• Problem 5: Using these 2 groups: Group3={CDGLOBAL=1} vs. Group4={CDGLOBAL=0}, compute the correlations between the systolic and diastolic blood pressure (VSBPSYS and VSBPDIA) within each group (r3 and r4). Then test a hypothesis for the equivalence of these correlations.
• Problem 6: Fit a simple linear model for VSTEMP and Weight_Kg. Formulate and assess a hypothesis about trivial slope of the regression curve on these two variables. Elaborate on your findings.

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