Finding the Fourth Proportional to 1,687.98, 2,529.81 and 712.74

Step by Step Solution

1. Step 1: Write the proportion equation
   1,687.98 : 2,529.81 = 712.74 : x
2. Step 2: Convert to fraction form
   1,687.98/2,529.81 = 712.74/x
3. Step 3: Cross multiply
   1,687.98x = 2,529.81 × 712.74
4. Step 4: Simplify right side
   1,687.98x = 1,803,096.78
5. Step 5: Solve for x
   x = 1,803,096.78/1,687.98
6. Step 6: Final answer
   x = 1,068.20