Finding the Fourth Proportional to 1,105.29, 1,655.61 and 520.79

Step by Step Solution

1. Step 1: Write the proportion equation
   1,105.29 : 1,655.61 = 520.79 : x
2. Step 2: Convert to fraction form
   1,105.29/1,655.61 = 520.79/x
3. Step 3: Cross multiply
   1,105.29x = 1,655.61 × 520.79
4. Step 4: Simplify right side
   1,105.29x = 862,216.85
5. Step 5: Solve for x
   x = 862,216.85/1,105.29
6. Step 6: Final answer
   x = 780.08