Final answer:
The population growth rate of frogs from April to August, accounting for additions and losses, results in a 517% increase, which does not match any provided options, indicating a potential error or typo in the question.
While none of the given options (A) 66%, (B) 76%, (C) 86%, (D) 96% matches our calculation, the procedure is correct.
Step-by-step explanation:
To calculate the population growth rate of the frogs in the ravine from April to August, we must first account for the changes in the population. We start with an initial population of 42 frogs in April. In May, the population is increased by 263 tadpoles. However, 26 tadpoles died due to pesticide runoff, and predators consumed 8 frogs. Then, in July, 12 frogs were run over by construction workers. To find the final population, we perform the following calculations:
- Initial population of frogs: 42
- Addition of tadpoles: +263
- Death of tadpoles due to pesticide: -26
- Frogs consumed by predators: -8
- Frogs run over by construction: -12
Calculating the final population:
- 42 (initial) + 263 (tadpoles) - 26 (dead tadpoles) - 8 (predated frogs) - 12 (run over frogs) = 259 (final population)
To find the growth rate, we use the formula:
Growth rate = (Final population - Initial population) / Initial population ×100%
Plugging in our numbers:
Growth rate = (259 - 42) / 42 ×100% = 517%
It should be noted that this might be a typo in the provided options or an error in the question as the actual growth rate significantly exceeds those values.