Finding the Fourth Proportional to 2,216.38, 3,058.56 and 1,221.63

Step by Step Solution

1. Step 1: Write the proportion equation
   2,216.38 : 3,058.56 = 1,221.63 : x
2. Step 2: Convert to fraction form
   2,216.38/3,058.56 = 1,221.63/x
3. Step 3: Cross multiply
   2,216.38x = 3,058.56 × 1,221.63
4. Step 4: Simplify right side
   2,216.38x = 3,736,428.65
5. Step 5: Solve for x
   x = 3,736,428.65/2,216.38
6. Step 6: Final answer
   x = 1,685.83