Finding the Fourth Proportional to 1,105.42, 1,657.32 and 520.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,105.42 : 1,657.32 = 520.12 : x
2. Step 2: Convert to fraction form
   1,105.42/1,657.32 = 520.12/x
3. Step 3: Cross multiply
   1,105.42x = 1,657.32 × 520.12
4. Step 4: Simplify right side
   1,105.42x = 862,005.28
5. Step 5: Solve for x
   x = 862,005.28/1,105.42
6. Step 6: Final answer
   x = 779.80