Respuesta :

9514 1404 393

Answer:

  400

Step-by-step explanation:

The statement of proportionality means the ratio of y to √x is the same. Then we can write ...

  (√x)/100 = (√81)/45

  √x = 100(√81)/45 = 20 . . . . . multiply by 100

  x = 20² = 400

x is 400 when y is 100.