Finding the Fourth Proportional to 2,200.24, 3,300.64 and 813.80

Step by Step Solution

1. Step 1: Write the proportion equation
   2,200.24 : 3,300.64 = 813.80 : x
2. Step 2: Convert to fraction form
   2,200.24/3,300.64 = 813.80/x
3. Step 3: Cross multiply
   2,200.24x = 3,300.64 × 813.80
4. Step 4: Simplify right side
   2,200.24x = 2,686,060.83
5. Step 5: Solve for x
   x = 2,686,060.83/2,200.24
6. Step 6: Final answer
   x = 1,220.80