Final answer:
The hypothesis should be based on the observation that cooler temperatures in a lake result in catching more fish. Hypotheses could include the effect of temperature on oxygen levels in the water and the impact on fish catch rates.
Step-by-step explanation:
Your hypothesis should be based on the information provided, which states that the cooler the temperature in a lake, the more oxygen the water holds. Since Daniel notices that he catches more fish in a lake that is cooler than 55 degrees, the hypothesis should reflect this observation.
a) If the temperature is cooler than 55 degrees, then Daniel will catch more fish because the cooler temperature means that the water holds more oxygen, which is beneficial for fish. This hypothesis is supported by the fact that fish require oxygen to survive, and more oxygen in the water increases their chances of being caught.
b) If the temperature is warmer than 55 degrees, then Daniel will catch fewer fish because the warmer temperature means that the water holds less oxygen, which is detrimental for fish. This hypothesis is based on the understanding that fish rely on oxygen-rich water for survival, and less oxygen in the water decreases their chances of being caught.