Finding the Fourth Proportional to 2,218.78, 3,061.89 and 1,224.05

Step by Step Solution

1. Step 1: Write the proportion equation
   2,218.78 : 3,061.89 = 1,224.05 : x
2. Step 2: Convert to fraction form
   2,218.78/3,061.89 = 1,224.05/x
3. Step 3: Cross multiply
   2,218.78x = 3,061.89 × 1,224.05
4. Step 4: Simplify right side
   2,218.78x = 3,747,906.45
5. Step 5: Solve for x
   x = 3,747,906.45/2,218.78
6. Step 6: Final answer
   x = 1,689.17