Finding the Fourth Proportional to 2,200.31, 3,300.56 and 813.39

Step by Step Solution

1. Step 1: Write the proportion equation
   2,200.31 : 3,300.56 = 813.39 : x
2. Step 2: Convert to fraction form
   2,200.31/3,300.56 = 813.39/x
3. Step 3: Cross multiply
   2,200.31x = 3,300.56 × 813.39
4. Step 4: Simplify right side
   2,200.31x = 2,684,628.03
5. Step 5: Solve for x
   x = 2,684,628.03/2,200.31
6. Step 6: Final answer
   x = 1,220.11