Answer:
C. 78.3% of the variation in length of eruption is explained by the least-squares regression equation.
Step-by-step explanation:
The coefficient of determination R-square is used to determine the explained variation in dependent variable explained by the least square regression line.
We know that independent variable in the given scenario is time of eruptions (x) and dependent variable is length of eruptions (y). We are given that coefficient of determination is 78.3%.
Thus, the 78.3% of variation in length of eruption is explained by the least square regression equation.