Finding the Fourth Proportional to 123,478.20, 170,402.70 and 72,505.56

Step by Step Solution

1. Step 1: Write the proportion equation
   123,478.20 : 170,402.70 = 72,505.56 : x
2. Step 2: Convert to fraction form
   123,478.20/170,402.70 = 72,505.56/x
3. Step 3: Cross multiply
   123,478.20x = 170,402.70 × 72,505.56
4. Step 4: Simplify right side
   123,478.20x = 12,355,143,189.01
5. Step 5: Solve for x
   x = 12,355,143,189.01/123,478.20
6. Step 6: Final answer
   x = 100,059.31