Finding the Fourth Proportional to 1,399.82, 2,099.52 and 425.81

Step by Step Solution

1. Step 1: Write the proportion equation
   1,399.82 : 2,099.52 = 425.81 : x
2. Step 2: Convert to fraction form
   1,399.82/2,099.52 = 425.81/x
3. Step 3: Cross multiply
   1,399.82x = 2,099.52 × 425.81
4. Step 4: Simplify right side
   1,399.82x = 893,996.61
5. Step 5: Solve for x
   x = 893,996.61/1,399.82
6. Step 6: Final answer
   x = 638.65