Final answer:
The shaded rows in Sasha's hundredths decimal model represent a factor of 0.09.
Step-by-step explanation:
To determine the factor that represents the shaded rows in Sasha's hundredths decimal model, we need to first understand the relationship between columns and rows in the model. Since the model represents the product of 0.72, we can think of each column as representing a factor of 0.01. Therefore, if Sasha shaded 9 columns, the shaded rows would represent a factor of 0.09 (9 x 0.01).