Finding the Fourth Proportional to 1,333.30, 2,002.79 and 813.55

Step by Step Solution

1. Step 1: Write the proportion equation
   1,333.30 : 2,002.79 = 813.55 : x
2. Step 2: Convert to fraction form
   1,333.30/2,002.79 = 813.55/x
3. Step 3: Cross multiply
   1,333.30x = 2,002.79 × 813.55
4. Step 4: Simplify right side
   1,333.30x = 1,629,369.80
5. Step 5: Solve for x
   x = 1,629,369.80/1,333.30
6. Step 6: Final answer
   x = 1,222.06