Finding the Fourth Proportional to 1,111.96, 1,667.33 and 418.80

Step by Step Solution

1. Step 1: Write the proportion equation
   1,111.96 : 1,667.33 = 418.80 : x
2. Step 2: Convert to fraction form
   1,111.96/1,667.33 = 418.80/x
3. Step 3: Cross multiply
   1,111.96x = 1,667.33 × 418.80
4. Step 4: Simplify right side
   1,111.96x = 698,275.71
5. Step 5: Solve for x
   x = 698,275.71/1,111.96
6. Step 6: Final answer
   x = 627.97