Answer:
28 percent of volcanoes are known to be active in that region.
Explanation:
Total number of volcanoes in a region = 449
Total number of active volcanoes in that region = 128
Percent of an active volcanoes :
[tex]\frac{\text{active volcanoes}}{\text{total volcanoes}}\times 100[/tex]
[tex]=\frac{128}{449}\times 100=28.51\%\approx 28\%[/tex]
28 percent of volcanoes are known to be active in that region.