Finding the Fourth Proportional to 2,216.63, 3,058.91 and 1,221.89

Step by Step Solution

1. Step 1: Write the proportion equation
   2,216.63 : 3,058.91 = 1,221.89 : x
2. Step 2: Convert to fraction form
   2,216.63/3,058.91 = 1,221.89/x
3. Step 3: Cross multiply
   2,216.63x = 3,058.91 × 1,221.89
4. Step 4: Simplify right side
   2,216.63x = 3,737,630.14
5. Step 5: Solve for x
   x = 3,737,630.14/2,216.63
6. Step 6: Final answer
   x = 1,686.18