Tomato Plant Growth

Question

Marissa wanted to see how the amount of water given to tomato plants affected their growth. She had six tomato plants that she split into two groups of three. She watered each plant in group 1 with 300ml of distilled water per day. Group 2 plants each received 500ml of distilled water each day. She measured each tomato plant’s height after 30 days and recorded her findings in the table below.
Group 1 - Plant A = 20 Plant B =25 Plant C =18
Group 2 - Plant A = 32 Plant B 38 Plant C = 44

1. What is the average height in cm for plants in group 1? *
18 cm
21 cm <----
42 cm
63 cm
2. What is the average height in cm for plants in group 2? *
38 cm <---
56 cm
97 cm
114 cm
3. Identify the independent variable in his experiment. *
Type of plant
Height of the plants <---
Amount of water
30 days
4. Identify the dependent variable in his experiment. *
Type of plant <----
Height of the plants
Amount of water
30 days
5. Which of the following correctly lists constants that are used or should be used in this experiment? *
Amount of water, final height of the plants, using three groups
Type of plant, using distilled water, type of soil, amount of sunlight exposure, how the plants are measured
Height of the plant, amount of water, using different pots
Type of plant, using different pots, using different amounts of soil

Answer 1

1 and 2 are correct.
I believe you should rethink 3 and 4
See this link.
https://www.thoughtco.com/independent-and-dependent-variables-differences-606115

Answer 2

Okay, Thanks!