Is Gregory correct or not?

yes he is because it can be exreesed as a ratio of two interges

Step-by-step explanation:

convert -6.9 to a fraction and you get 9/10

it will cost dollar $540

the living room is 3 which means if we divide 325/3 then we get $108

therefore if 1part of the living room cost $108 and 3 costed $325

then total 5part of the room will cost 5*108 which gives $540