Finding the Fourth Proportional to 1,111.84, 1,667.20 and 418.48

Step by Step Solution

1. Step 1: Write the proportion equation
   1,111.84 : 1,667.20 = 418.48 : x
2. Step 2: Convert to fraction form
   1,111.84/1,667.20 = 418.48/x
3. Step 3: Cross multiply
   1,111.84x = 1,667.20 × 418.48
4. Step 4: Simplify right side
   1,111.84x = 697,689.86
5. Step 5: Solve for x
   x = 697,689.86/1,111.84
6. Step 6: Final answer
   x = 627.51