Final answer:
To determine Tanina's plant height after the second week, we add the growth (0.5 decimeters) to its original height (4.78 decimeters), resulting in a height of 5.28 decimeters.
Step-by-step explanation:
To figure out how tall Tanina's plant was at the end of the second week, we simply need to add the growth from that week to the plant's initial height. The plant started at 4.78 decimeters and then grew an additional 0.5 decimeters.
Let's do the math:
- Starting height of the plant: 4.78 dm
- Plus the growth in the second week: + 0.5 dm
- Total height at the end of the second week: 4.78 dm + 0.5 dm = 5.28 decimeters.
Therefore, Tanina's plant was 5.28 decimeters tall at the end of the second week.