Answer:
The mass ratio of oxygen rounded to the nearest whole no. 3 : 2
Step-by-step explanation:
According to Law of Multiple proportion when two elements combine to make two or more different compounds, the mass ratio of the two element in the first compound, when divided by the mass ratio of the second compound , form a simple whole number ratio.
 Compound A contains 1.34 g of sulfur for every 0.86 g of oxygen
 

Compound B contains 11.63 g of sulfur for every 10.49 g of oxygen
 

Ratio of oxygen in each compound 
 always put the larger number over the smaller number.
