No.
It is greater than. 3/4 turns into 6/8.
"is greater than" >
Four ninths is less than eight sixteenths.
No.
Yes, four-fifths is greater than four-eighths.
Four fifths is less.
No, they are both a half.
no it is equal
Whether you are counting people, cookies, books, seventeenths, etc., fifteen is greater than four.
Convert them to the same denominator and the answer to your question will be immediately apparent (assuming you know that six is less than seven).
They are equal