Finding the Fourth Proportional to 1,111.91, 1,668.17 and 381.54

Step by Step Solution

1. Step 1: Write the proportion equation
   1,111.91 : 1,668.17 = 381.54 : x
2. Step 2: Convert to fraction form
   1,111.91/1,668.17 = 381.54/x
3. Step 3: Cross multiply
   1,111.91x = 1,668.17 × 381.54
4. Step 4: Simplify right side
   1,111.91x = 636,471.67
5. Step 5: Solve for x
   x = 636,471.67/1,111.91
6. Step 6: Final answer
   x = 572.42