Finding the Fourth Proportional to 3,783.55, 5,221.55 and 2,105.11

Step by Step Solution

1. Step 1: Write the proportion equation
   3,783.55 : 5,221.55 = 2,105.11 : x
2. Step 2: Convert to fraction form
   3,783.55/5,221.55 = 2,105.11/x
3. Step 3: Cross multiply
   3,783.55x = 5,221.55 × 2,105.11
4. Step 4: Simplify right side
   3,783.55x = 10,991,948.91
5. Step 5: Solve for x
   x = 10,991,948.91/3,783.55
6. Step 6: Final answer
   x = 2,905.20