Finding the Fourth Proportional to 1,025.91, 1,539.50 and 615.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,025.91 : 1,539.50 = 615.15 : x
2. Step 2: Convert to fraction form
   1,025.91/1,539.50 = 615.15/x
3. Step 3: Cross multiply
   1,025.91x = 1,539.50 × 615.15
4. Step 4: Simplify right side
   1,025.91x = 947,020.35
5. Step 5: Solve for x
   x = 947,020.35/1,025.91
6. Step 6: Final answer
   x = 923.10