Finding the Fourth Proportional to 3,930.10, 5,421.72 and 2,355.46

Step by Step Solution

1. Step 1: Write the proportion equation
   3,930.10 : 5,421.72 = 2,355.46 : x
2. Step 2: Convert to fraction form
   3,930.10/5,421.72 = 2,355.46/x
3. Step 3: Cross multiply
   3,930.10x = 5,421.72 × 2,355.46
4. Step 4: Simplify right side
   3,930.10x = 12,770,644.59
5. Step 5: Solve for x
   x = 12,770,644.59/3,930.10
6. Step 6: Final answer
   x = 3,249.45