Answer:
To expand the sample of lizards while maintaining its integrity, the biologist should consider the following:
1. **Random Sampling:** Ensure that the new sample is randomly selected from the same population as the original sample. This helps avoid bias and ensures that the expanded sample is representative of the entire population of lizards in that area.
2. **Preserve Original Distribution:** If the weights of the lizards in the original sample are normally distributed, efforts should be made to maintain this distribution in the expanded sample. This involves selecting new lizards in a way that preserves the characteristics of the original normal distribution, so the expanded sample accurately reflects the population.
3. **Consistency in Data Collection:** Use consistent methods for measuring and recording the weights of the lizards in both the original and expanded samples. Any changes in measurement techniques or conditions may introduce variability and compromise the integrity of the comparison between the two samples.
4. **Record Environmental Factors:** Take note of environmental factors that may influence lizard weights. If possible, control for these factors or ensure that the expanded sample represents similar environmental conditions as the original sample.
5. **Over Time:** Regularly monitor the weights of the lizards over time to account for any temporal variations in their size or characteristics. This ensures that the expanded sample captures potential changes in the lizard population as it evolves.
By following these steps, the biologist can systematically expand the sample while maintaining the integrity of the data, allowing for reliable comparisons and generalizations about the lizard population in that area.