Finding the Fourth Proportional to 2,216.09, 3,058.17 and 1,221.35

Step by Step Solution

1. Step 1: Write the proportion equation
   2,216.09 : 3,058.17 = 1,221.35 : x
2. Step 2: Convert to fraction form
   2,216.09/3,058.17 = 1,221.35/x
3. Step 3: Cross multiply
   2,216.09x = 3,058.17 × 1,221.35
4. Step 4: Simplify right side
   2,216.09x = 3,735,095.93
5. Step 5: Solve for x
   x = 3,735,095.93/2,216.09
6. Step 6: Final answer
   x = 1,685.44