Finding the Fourth Proportional to 1,418.71, 2,128.50 and 725.87

Step by Step Solution

1. Step 1: Write the proportion equation
   1,418.71 : 2,128.50 = 725.87 : x
2. Step 2: Convert to fraction form
   1,418.71/2,128.50 = 725.87/x
3. Step 3: Cross multiply
   1,418.71x = 2,128.50 × 725.87
4. Step 4: Simplify right side
   1,418.71x = 1,545,014.30
5. Step 5: Solve for x
   x = 1,545,014.30/1,418.71
6. Step 6: Final answer
   x = 1,089.03