Finding the Fourth Proportional to 1,387.52, 1,910.40 and 1,126.40

Step by Step Solution

1. Step 1: Write the proportion equation
   1,387.52 : 1,910.40 = 1,126.40 : x
2. Step 2: Convert to fraction form
   1,387.52/1,910.40 = 1,126.40/x
3. Step 3: Cross multiply
   1,387.52x = 1,910.40 × 1,126.40
4. Step 4: Simplify right side
   1,387.52x = 2,151,874.56
5. Step 5: Solve for x
   x = 2,151,874.56/1,387.52
6. Step 6: Final answer
   x = 1,550.88