Finding the Fourth Proportional to 1,018.50, 1,405.56 and 625.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,018.50 : 1,405.56 = 625.50 : x
2. Step 2: Convert to fraction form
   1,018.50/1,405.56 = 625.50/x
3. Step 3: Cross multiply
   1,018.50x = 1,405.56 × 625.50
4. Step 4: Simplify right side
   1,018.50x = 879,177.78
5. Step 5: Solve for x
   x = 879,177.78/1,018.50
6. Step 6: Final answer
   x = 863.21