Finding the Fourth Proportional to 1,112.16, 1,667.47 and 418.69

Step by Step Solution

1. Step 1: Write the proportion equation
   1,112.16 : 1,667.47 = 418.69 : x
2. Step 2: Convert to fraction form
   1,112.16/1,667.47 = 418.69/x
3. Step 3: Cross multiply
   1,112.16x = 1,667.47 × 418.69
4. Step 4: Simplify right side
   1,112.16x = 698,153.01
5. Step 5: Solve for x
   x = 698,153.01/1,112.16
6. Step 6: Final answer
   x = 627.75