Finding the Fourth Proportional to 2,216.22, 3,058.46 and 1,221.57

Step by Step Solution

1. Step 1: Write the proportion equation
   2,216.22 : 3,058.46 = 1,221.57 : x
2. Step 2: Convert to fraction form
   2,216.22/3,058.46 = 1,221.57/x
3. Step 3: Cross multiply
   2,216.22x = 3,058.46 × 1,221.57
4. Step 4: Simplify right side
   2,216.22x = 3,736,116.87
5. Step 5: Solve for x
   x = 3,736,116.87/2,216.22
6. Step 6: Final answer
   x = 1,685.81