Finding the Fourth Proportional to 1,111.98, 1,668.12 and 381.61

Step by Step Solution

1. Step 1: Write the proportion equation
   1,111.98 : 1,668.12 = 381.61 : x
2. Step 2: Convert to fraction form
   1,111.98/1,668.12 = 381.61/x
3. Step 3: Cross multiply
   1,111.98x = 1,668.12 × 381.61
4. Step 4: Simplify right side
   1,111.98x = 636,571.27
5. Step 5: Solve for x
   x = 636,571.27/1,111.98
6. Step 6: Final answer
   x = 572.47