Two students conduct a study to investigate the relationship between forearm length and height. Maria measures the subjects in centimeters. In a scatterplot of the data she sees a linear relationship between the variables, so she calculates the correlation coefficient. She determines that r = 0.86. John measures the same subjects in inches. He also calculates the correlation coefficient. What do you expect the correlation will be for John’s measurements?

r = 0.86

Explanation:

Correlation coefficients are the strength of the relationship between two variables.

Correlations can indicate anywhere between

Looking at sample correlation coefficient formula which says

= ÷ ( × )

where and are the sample deviations and is the sample covariance, all of which will remain the same for Maria and John.

Hence, John's correlation will be approximately 0.86 since he would have approximately the same measurement as Maria's measurement when Maria's measurement is converted from centimeters to inches.