This is a GREAT example of proportional relationships because the data tables on #'s 1 and 2 show $10 being made each hour, but the graph has a missing slope triangle that is exactly pointed out as "$40 in 4 hours".

 

This problem also demonstrates that the unit rate is the slope of the graph because the data is attached to the graph. You can see that the data is lined up with the graph:

 

"Money" (Y) - The data going UP.

 

"Hours" (X) - The data going RIGHT.

 

The answer to #9 is NOT a unit rate because if you look closely where it has "$20" (and I'm probably going on the wrong track here, but anyway...), I think was supposed to be "$10 earned". Also it's not "$20 per 2 hours", because it starts with $10 earned in the first hour, so in conclusion, the POSSIBLY (and I mean POSSIBLY!) correct answer might be this:

 

$10 earned

________

1 hour

 

Sorry I didn't really solve why the slope triangle for $40 earned in 4 hours was missing----I just wanted to finish this with some time to spare.