We know that Ryhanna has a container with a volume of 1.5 liters and that she estimates the value to be 2.1 liters. We want to find the percent error.
For doing so, we remember that the percent error is given by the expression:
In this exercise, we have that:
So, replacing we obtain:
This means that Ryhanna estimated the value of the volume with an error of 40%.