Finding the Fourth Proportional to 1,096.34, 1,643.55 and 518.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,096.34 : 1,643.55 = 518.78 : x
2. Step 2: Convert to fraction form
   1,096.34/1,643.55 = 518.78/x
3. Step 3: Cross multiply
   1,096.34x = 1,643.55 × 518.78
4. Step 4: Simplify right side
   1,096.34x = 852,640.87
5. Step 5: Solve for x
   x = 852,640.87/1,096.34
6. Step 6: Final answer
   x = 777.72