Finding the Fourth Proportional to 1,038.88, 1,550.72 and 915.87

Step by Step Solution

1. Step 1: Write the proportion equation
   1,038.88 : 1,550.72 = 915.87 : x
2. Step 2: Convert to fraction form
   1,038.88/1,550.72 = 915.87/x
3. Step 3: Cross multiply
   1,038.88x = 1,550.72 × 915.87
4. Step 4: Simplify right side
   1,038.88x = 1,420,250.17
5. Step 5: Solve for x
   x = 1,420,250.17/1,038.88
6. Step 6: Final answer
   x = 1,367.10