Finding the Fourth Proportional to 2,216.78, 3,059.13 and 1,222.05

Step by Step Solution

1. Step 1: Write the proportion equation
   2,216.78 : 3,059.13 = 1,222.05 : x
2. Step 2: Convert to fraction form
   2,216.78/3,059.13 = 1,222.05/x
3. Step 3: Cross multiply
   2,216.78x = 3,059.13 × 1,222.05
4. Step 4: Simplify right side
   2,216.78x = 3,738,425.87
5. Step 5: Solve for x
   x = 3,738,425.87/2,216.78
6. Step 6: Final answer
   x = 1,686.42