Answer:
Scientist's conclusion might be wrong and needs to be probed further with experiments
Step-by-step explanation:
In the experiment the mice was observed first at day 0 and then directly at day 500. When the scientist found 3 mice suffering from lung cancer at day 500 she gave the conclusion that the mice need to be exposed for 500 or more days for developing lung cancer. But there is a huge duration gap of 500 days between her first and second experimental group. The mice could have developed cancer anywhere between 0 and 500 days so now she needs to break this duration into smaller gaps and repeat the experiment to narrow down the result. She needs to expose the mice to smoke at varying duration between 0 and 500 days. After she gets a result in this second experiment, she needs to further narrow down the gap till she arrives at a definite conclusion.