Answer: 
The empirical formula is SiBr₂I₂.
Step-by-step explanation:
We can’t calculate the molecular formula, because we don’t know the molar mass of the compound. 
Assume that you have 100 g of the compound. 
Then you have 6.360 g Si, 36.18 g Br, and 57.46 g I. 
1. Calculate the moles of each element. 
Moles of Si = 6.360× 1/28.08 = 0.2265 mol Si 
Moles of Br = 36.18 × 1/79.90 = 0.4528 mol Br 
Moles of I = 57.46 × 1/126.90 = 0.4449 mol I 
=============== 
2. Calculate the molar ratios. 
Divide all values by the smallest number. 
Si: 0.2265/0.2265 = 1 
Br: 0.4528/0.2265 = 2.000 
I: 0.4449/0.2265 = 1.964 
=============== 
3. Determine the empirical formula 
Round off all numbers to the closest integer. 
Si: 1 
Br: 2 
I: 2 
The empirical formula is SiBr₂I₂.