WEEK 5: ASSIGNMENT 8 - PEARSON CORRELATION COEFFICIENT
Q->Q: Quantitative vs Quantitative
I am going to analyze the relationship between the following two quantitative variables, with the Pearson Correlation Coefficient, r.
S2AQ8C – Largest number of drinks of any alcohol usually consumed on days when drank alcohol in last 12 months (1-80 drinks)
AGE – Age of adults (30 – 45 years old)
Figure 1 shows the scatter plot of the two variables (AGE: Explanatory and S2AQ8C: Response). And there you can see a positive negative trend that is a value of r less than zero. Nevertheless, the relationship is not so strong, as you can see.
From the analysis of the Correlation Coefficient, shown in Figure 2, we determine that there is a significant relationship (p<,0001 that is p<0,05) but it is weak, because the r value is very close to zero (r = -0,048).
And Figure 3 shows the procedure used in SAS.
That means that if we know the “AGE” we can predict we can predict 0.23% (r˄2=0,0023) of the variability in the largest number of drinks of any alcohol usually consumed on days when drank alcohol in the last 12 months.
