Multiplying aggregate sum with another variable 'list*float' errors?

Hello all.
I've taken a list of numbers, made their aggregate sum, and created a variable with that value.
I've also found the value that I want to multiply this aggregate sum variable with.
I can run everything successfully up to this point. I can have my response show my list with the aggregate sum and its table reference Id, I can have it show the variable that is that sum, I can have it show the variable that is the value I wan't to multiply that sum with.
But when I go and multiply the two, I get a variety of errors each way I'm attempting it.
I get 'list*float' error most commonly.
Any thoughts on how to fix this?
I've tried making a new variable that is the previous 2 multiplied, and just tried updating variables even and can't get it to respond correctly.