Chapter 3: Correlation Transformation Investigation
Find the Correlation Height in Feet Weight in pounds R = 0.97
Find the Correlation Height in Inches Weight in pounds R = 0.97 Height in Feet Weight in pounds
Find the Correlation…The person measuring height was off by 2 inches. Each person is actually 2 inches shorter than reported previously. Height in Inches Weight in pounds R = 0.97 Height in Inches Weight in pounds
Find the Correlation…The scale was incorrect; each person is actually 5 pounds heavier than previously reported. Height in Inches Weight in pounds R = 0.97 Height in Inches Weight in pounds
Find the Correlation…The scale was incorrect; each person is actually 5 pounds heavier than previously reported. Height in Inches Weight in pounds R = 0.97 Height in Inches Weight in pounds
Why?! Since r is calculated using standardized values (z-scores), the correlation value will not change if the units of measure are changed (feet to inches, etc.) Adding a constant to either x or y or both will not change the correlation because neither the standard deviation nor distance from the mean will be impacted.