To determine which student made a mistake in her statement, let's evaluate the statements step by step:
1. Irma's Statement:
- Irma stated that she used a ruler to measure the radius and then calculated the volume of the tennis ball to be 104 cm³.
2. Julia's Statement:
- Julia stated that she used a scale to measure the mass of the tennis ball, which she found to be 0.6 lb.
3. Grace's Statement:
- Grace stated that she used a scale to measure the weight of the tennis ball, which she found to be 0.28 lb.
4. Masha's Statement:
- Masha stated that she used a bucket of water and a ruler to measure the volume of the tennis ball, which she found to be 98 cm³.
Now let's analyze the obtained results:
- Irma provided a volume of 104 cm³.
- Masha provided a volume of 98 cm³.
Since both students measured the volume of the same tennis ball but obtained different values (104 cm³ and 98 cm³), there is a discrepancy between their measurements. This indicates a potential error.
Given these observations, the student who made a mistake in her statement is Irma, as her measured volume differs from Masha's volume, which might be more accurate due to the method used (volume displacement by water is typically more reliable).
Conclusion:
The student who made a mistake in her statement is Irma.
