Finding the Fourth Proportional to 1,043.35, 1,439.72 and 623.61

Step by Step Solution

1. Step 1: Write the proportion equation
   1,043.35 : 1,439.72 = 623.61 : x
2. Step 2: Convert to fraction form
   1,043.35/1,439.72 = 623.61/x
3. Step 3: Cross multiply
   1,043.35x = 1,439.72 × 623.61
4. Step 4: Simplify right side
   1,043.35x = 897,829.19
5. Step 5: Solve for x
   x = 897,829.19/1,043.35
6. Step 6: Final answer
   x = 860.53