The mass of the wall will be
You're dealing with a pretty straightforward unit conversion problem. Like with most such problems, there are many ways in which to reach the desired result, which in this case is mass expressed in pounds.
I'll show you one of those ways. So, since density is given to you in
Now you need to determine the volume of the wall. Since you're basically dealing with a rectangular prism, the volume will be equal to
You need however to express this volume in
At this point, you have what you need to determine the mass of the wall in
All you need to do from this point on is to convert the mass to pounds