Finding the Fourth Proportional to 1,320.55, 1,981.59 and 540.43

Step by Step Solution

1. Step 1: Write the proportion equation
   1,320.55 : 1,981.59 = 540.43 : x
2. Step 2: Convert to fraction form
   1,320.55/1,981.59 = 540.43/x
3. Step 3: Cross multiply
   1,320.55x = 1,981.59 × 540.43
4. Step 4: Simplify right side
   1,320.55x = 1,070,903.03
5. Step 5: Solve for x
   x = 1,070,903.03/1,320.55
6. Step 6: Final answer
   x = 810.96