My first thought is that your sketch is not fully defined, you should make sure of that. Second, even if you have the correct model, are you using the correct density for the material on your part? If they are telling you it should be Aluminum and you have Steel, you won't get the correct answer either. Do you have the whole test available, or post the link to it?
The sketch is now fully defined, but that did not change my mass.
My applied material is the AISI 1020 Steel, which is what the sample exam asked for.
A link to download the pdf can be found at Certified SOLIDWORKS Associate Exam | SOLIDWORKS
and there is a quick link on the right.
The image of your constrained sketch in not real clear.
Attach the *.sldprt file here.
My general thought is that if you are not automatically using the origin at a logical location for fully constraining sketches (as in your first image) you are not yet ready for the CSWA. That should come without a second thought. Reflex action.
I have just reproduced the sketch quickly & extruded with the specified material & I get a Mass = 939.54 grams. Are you sure you are extruding to a depth of 43? Have you checked you have selected the correct units for the part? Have you accidently added a shallow draft to your part when extruding?