Finding the Fourth Proportional to 2,199.43, 3,300.81 and 813.61

Step by Step Solution

1. Step 1: Write the proportion equation
   2,199.43 : 3,300.81 = 813.61 : x
2. Step 2: Convert to fraction form
   2,199.43/3,300.81 = 813.61/x
3. Step 3: Cross multiply
   2,199.43x = 3,300.81 × 813.61
4. Step 4: Simplify right side
   2,199.43x = 2,685,572.02
5. Step 5: Solve for x
   x = 2,685,572.02/2,199.43
6. Step 6: Final answer
   x = 1,221.03