Finding the Fourth Proportional to 2,216.52, 3,058.62 and 1,221.78

Step by Step Solution

1. Step 1: Write the proportion equation
   2,216.52 : 3,058.62 = 1,221.78 : x
2. Step 2: Convert to fraction form
   2,216.52/3,058.62 = 1,221.78/x
3. Step 3: Cross multiply
   2,216.52x = 3,058.62 × 1,221.78
4. Step 4: Simplify right side
   2,216.52x = 3,736,960.74
5. Step 5: Solve for x
   x = 3,736,960.74/2,216.52
6. Step 6: Final answer
   x = 1,685.96