Finding the Fourth Proportional to 2,216.01, 3,057.98 and 1,221.09

Step by Step Solution

1. Step 1: Write the proportion equation
   2,216.01 : 3,057.98 = 1,221.09 : x
2. Step 2: Convert to fraction form
   2,216.01/3,057.98 = 1,221.09/x
3. Step 3: Cross multiply
   2,216.01x = 3,057.98 × 1,221.09
4. Step 4: Simplify right side
   2,216.01x = 3,734,062.69
5. Step 5: Solve for x
   x = 3,734,062.69/2,216.01
6. Step 6: Final answer
   x = 1,685.04