You need 3 for ? to make this sentence true, because if you place 3 for ?, 736,554<736,573<736,589 makes sense. If you compare the three numbers, 736,554 is the smallest, then 736,573, and 736,587 is the biggest number. Hope this answered your question!
X=3; you can set up a proportion using the slope equation. So (y[sub2]-y[sub1])/(x[sub2]-x[sub1])=2/1 then plug in the values and simplify. Then cross multiply and solve for x. Rest of work shown in the picture