The table below shows the results of a study that investigated the effect of temperature and light on the yield of tomatoes in to greenhouse on a farm .
Average yield of tomatoes per plant
Temperature low light levels High light levels
5 0,5 0,5
10 1,5 2,5
15 3,0 5,0
20 3,6 8,5
25 3,5 7,8
30 2,5 6.2
State two steps the investigator may have taken into consideration during the planning stage of the investigation
1. Controlled Variables: The investigator may have carefully controlled other factors that could affect the yield of tomatoes, such as the type of soil, amount of water, nutrients, and spacing between plants. By keeping these variables constant, the investigator can be more confident that any differences in yield are due to the temperature and light levels.
2. Randomization: The investigator may have randomly assigned the different temperature and light level treatments to the tomato plants in order to reduce bias and ensure that any observed effects are truly caused by the treatments. Randomization helps to ensure that the results are not due to chance or some other confounding factor.