Final answer:
To determine if the relationship between heart weight and length follows an exponential or power model, one must analyze the regression equation and data pattern. Factors like a linear model not fitting well and the nature of growth indicated by the data aid this determination. Without complete information, a definitive answer cannot be provided.
Step-by-step explanation:
Based on the information provided, discerning whether the relationship between heart weight and length follows an exponential model or a power model requires an analysis of the regression equation and the pattern of the data represented in a scatter plot. If the relationship expressed in the regression indicates that heart weight grows proportional to the length (option b), then it suggests a linear model. However, if it grows proportional to a certain power of the length (option a or d), then it would suggest a power model. Since there is a mention that only 1.5 percent of the variation is explained by a linear regression, it implies that a linear model may not be the best fit. To make a definitive decision between exponential and power models, one would look for a consistent percentage rate of change over time (exponential growth) or changes related to the power of another variable (power growth). If the data plotted on a logarithmic scale forms a straight line, this is consistent with an exponential relationship.
Without a scatter plot or the actual regression equation from the transformations, any suggestion of the model would be speculative. However, considering the mention that an exponential model is often overly simplistic and assumes increasing growth rate as size increases, there may be an implication that the relationship follows an exponential pattern, but other context provided in the question hints toward a power relationship. The reference to population growth and energy usage increasing at a nearly exponential rate might provide additional context, but it is not directly related to heart weight and length. Therefore, the most accurate answer would require further information about the specific transformations conducted on the data.