[tex]\huge\boxed{Hi,\:hope\:you\:are\:having\:a\:splendiferous\:day!}[/tex]The digit that makes this statement true is 4.
Here's a trick to check if the number is divisible by 9.
We add all the digits together, and if the final result is 9, then the number is
[tex]\huge\bold{divisible\:by\:9}.[/tex]
If we plug in the digit 1, the final result won't be 9.
Same with 2, 3, 5, 6, 7, 8, 9 and 0.
Let's check 4:
7+7+8+1+4+5+4=14+9+9+4=14+18+4=14+22=36
3+6=9
[tex]\huge\boxed{Therefore, this\:number\:is\:divisible\:by\:9.}\\\huge\sf{Good\:luck!}\\\huge\underlined{Hope\:it\:helps!}\\\\{FelicitousTeen\:here\:to\:help}[/tex]
