Answer:YesStep-by-step explanation:Yes terminating and repeating decimals are rational numbers.This is a terminating decimal. It ends, so it is rational.Anything that can be written as a fraction where the top and bottom are integers is rational.Some examples: -1 =-1/15 =5/15.23 =523/100.3333333333333333333333333333333333333....=1/31 2/3 =5/3Since there seems to be more that need convincing, the number 128.439 can be written as 128439/1000that is a fraction where the top and bottom are integersso 128.439 is rational