Finding the Fourth Proportional to 377,905.55, 521,485.72 and 208,139.67

Step by Step Solution

1. Step 1: Write the proportion equation
   377,905.55 : 521,485.72 = 208,139.67 : x
2. Step 2: Convert to fraction form
   377,905.55/521,485.72 = 208,139.67/x
3. Step 3: Cross multiply
   377,905.55x = 521,485.72 × 208,139.67
4. Step 4: Simplify right side
   377,905.55x = 108,541,865,150.16
5. Step 5: Solve for x
   x = 108,541,865,150.16/377,905.55
6. Step 6: Final answer
   x = 287,219.56