Finding the Fourth Proportional to 1,112.25, 1,666.55 and 381.42

Step by Step Solution

1. Step 1: Write the proportion equation
   1,112.25 : 1,666.55 = 381.42 : x
2. Step 2: Convert to fraction form
   1,112.25/1,666.55 = 381.42/x
3. Step 3: Cross multiply
   1,112.25x = 1,666.55 × 381.42
4. Step 4: Simplify right side
   1,112.25x = 635,653.59
5. Step 5: Solve for x
   x = 635,653.59/1,112.25
6. Step 6: Final answer
   x = 571.50