The correlation between agarwood formation size and the injection volume of fungal spores was statistically significant (P < 0.05). The regressed equation is y = 10.2 – 2.3x and the coefficient of d

The correlation coefficient (r) can be estimated from the coefficient of determination (R²). Since R² is the square of the correlation coefficient (r), you can find r by taking the square root of R². Here, R² is 0.76, so to get r, we'll take the square root of 0.76. However, because a correlation could be either positive or negative, the sign of the correlation coefficient depends on the slope of the regression line provided (y = 10.2 - 2.3x). Here the slope is negative, indicating a negative correlation. So, r = -√0.76, r = -0.87 approximately. This indicates a strong negative correlation between the agarwood formation size and the injection volume of fungal spores. This means as the injection volume of fungal spores increases, the agarwood formation size decreases.

The correlation coefficient (r) value for this relationship is -0.87.