Calculate baseline expected fpkm?

[M&M]

Is there a measure I could use to calculate a baseline expected fpkm per transcript based on sequencing coverage in a single sample? I'd then like to use this to compare with the fpkm generated from cufflinks in the isoforms.fpkm_tracking file and generate a p-value on the fpkm per isoform per sample. These are tumor samples and I don't have matched normals, so I'm trying to figure out an alternative