You purchase a cooler from a sneaky alien salesman. You are uncertain of what alien material it is made of so you decide

[answerhappygod]

You purchase a cooler from a sneaky alien salesman. You are
uncertain of what alien material it is made of so you decide to
test how well it acts as an insulator. You place 2kg of ice into
the cooler and it takes 30 minutes to melt. The surface area of the
cooler is 0.75m^2 and the thickness of the sides is 3cm. The
temperature inside of the cooler is 2 degrees Celsius and the
temperature outside of the cooler is 25 degrees Celsius. What is
the thermal conductivity of the material the cooler is made out of?
(answer: 0.64J/smC)