Answer: 1.5 meters.
Explanation:
Given: At the beginning of spring, the ice starts to melt.
The variable s models the ice sheets thickness in meters t weeks after the beginning of spring.

At t=0, s=4 meters
At t=1, s=3.75 meters
∴It is a linear equation, where the rate of change in thickness = 3.75-4=0.25 meter per minute .
The decrease in ice sheet in every 6 weeks =
