Finding the Fourth Proportional to 1,162.90, 1,604.82 and 638.92

Step by Step Solution

1. Step 1: Write the proportion equation
   1,162.90 : 1,604.82 = 638.92 : x
2. Step 2: Convert to fraction form
   1,162.90/1,604.82 = 638.92/x
3. Step 3: Cross multiply
   1,162.90x = 1,604.82 × 638.92
4. Step 4: Simplify right side
   1,162.90x = 1,025,351.59
5. Step 5: Solve for x
   x = 1,025,351.59/1,162.90
6. Step 6: Final answer
   x = 881.72