Finding the Fourth Proportional to 2,215.92, 3,057.98 and 1,221.29

Step by Step Solution

1. Step 1: Write the proportion equation
   2,215.92 : 3,057.98 = 1,221.29 : x
2. Step 2: Convert to fraction form
   2,215.92/3,057.98 = 1,221.29/x
3. Step 3: Cross multiply
   2,215.92x = 3,057.98 × 1,221.29
4. Step 4: Simplify right side
   2,215.92x = 3,734,670.47
5. Step 5: Solve for x
   x = 3,734,670.47/2,215.92
6. Step 6: Final answer
   x = 1,685.38