Finding the Fourth Proportional to 2,215.98, 3,058.07 and 1,221.29

Step by Step Solution

1. Step 1: Write the proportion equation
   2,215.98 : 3,058.07 = 1,221.29 : x
2. Step 2: Convert to fraction form
   2,215.98/3,058.07 = 1,221.29/x
3. Step 3: Cross multiply
   2,215.98x = 3,058.07 × 1,221.29
4. Step 4: Simplify right side
   2,215.98x = 3,734,790.31
5. Step 5: Solve for x
   x = 3,734,790.31/2,215.98
6. Step 6: Final answer
   x = 1,685.39