Final answer:
Caleb's plant will grow 1.2 centimeters in 3 weeks, since it grows at a steady rate of 0.4 centimeters per week.
Step-by-step explanation:
The student's question relates to the growth rate of a plant over a period of time. To calculate the total growth of the plant over three weeks, we simply multiply the weekly growth rate by the number of weeks. Given that the plant grows 0.4 centimeters each week, we perform the following calculation: 0.4 cm/week × 3 weeks = 1.2 cm
Therefore, in 3 weeks, the plant will have grown a total of 1.2 centimeters.