yes, it is direct proportion becuz in direct proportion if the prize of one quantity increases the other too will have to increase. here in this question as you can see 5melons were costing 3.50 and on increasing it to 7 melons cost is too increasing soo it is a direct proportion.
IF THIS ANSWER HEPLED YOU MARK IT AS BRAINLIIST OR ELSE IF YOU HAVE ANY DOUBTS ASK IN COMMENT