To find the answer, we need to compare the Mean Absolute Deviations (MAD) for the sixth graders and seventh graders.
The MAD for the sixth graders is 1.2, while the MAD for the seventh graders is 0.7.
To calculate how many times the variability in the heights of the seventh graders is the variability in the heights of the sixth graders, we divide the MAD of the seventh graders by the MAD of the sixth graders:
0.7 / 1.2 ≈ 0.58
So, the variability in the heights of the seventh graders is approximately 0.58 times the variability in the heights of the sixth graders. This rounds to 0.6.