Finding the Fourth Proportional to 1,018.78, 1,406.78 and 625.93

Step by Step Solution

1. Step 1: Write the proportion equation
   1,018.78 : 1,406.78 = 625.93 : x
2. Step 2: Convert to fraction form
   1,018.78/1,406.78 = 625.93/x
3. Step 3: Cross multiply
   1,018.78x = 1,406.78 × 625.93
4. Step 4: Simplify right side
   1,018.78x = 880,545.81
5. Step 5: Solve for x
   x = 880,545.81/1,018.78
6. Step 6: Final answer
   x = 864.31