Amount
OF
Fertilizer A Fertilizer B
Weekly Average Weekly Average
Growth (cm) Growth (cm)
Fertilizer
(kg)
25
15
2.8
46
13
0.3
33
1.8
25
0.2
Greg is testing two different types of fertilizer on his tomato plants to find the best conditions for his summer garden. He is
adding different amounts of fertilizers to his plants. Then he is recording how much the plants grow for 4 weeks. His data is
recorded in the data table.
In this experiment, the independent variable is the amount of fertilizer applied (Types A and B); the dependent variable is
the plant growth. What is the result when the independent variable is changed? Can you match these situations?
Both Fertilizer A and B
1.5kg fertilizer A
Expected results would be very low average weekly plant growth, <0.2cm
Increase in average weekly plant growth, increase fertilizer 1kg to 1.5kg
Results in the greatest weekly growth overall
Results in the least weekly plant growth overall
2.5kg fertilizer B
3.0kg fertilizer A or B