Finding the Fourth Proportional to 1,111.38, 1,666.73 and 418.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,111.38 : 1,666.73 = 418.15 : x
2. Step 2: Convert to fraction form
   1,111.38/1,666.73 = 418.15/x
3. Step 3: Cross multiply
   1,111.38x = 1,666.73 × 418.15
4. Step 4: Simplify right side
   1,111.38x = 696,932.73
5. Step 5: Solve for x
   x = 696,932.73/1,111.38
6. Step 6: Final answer
   x = 627.09