Finding the Fourth Proportional to 1,111.97, 1,667.70 and 418.71

Step by Step Solution

1. Step 1: Write the proportion equation
   1,111.97 : 1,667.70 = 418.71 : x
2. Step 2: Convert to fraction form
   1,111.97/1,667.70 = 418.71/x
3. Step 3: Cross multiply
   1,111.97x = 1,667.70 × 418.71
4. Step 4: Simplify right side
   1,111.97x = 698,282.67
5. Step 5: Solve for x
   x = 698,282.67/1,111.97
6. Step 6: Final answer
   x = 627.97