Finding the Fourth Proportional to 1,015.80, 1,401.81 and 550.05

Step by Step Solution

1. Step 1: Write the proportion equation
   1,015.80 : 1,401.81 = 550.05 : x
2. Step 2: Convert to fraction form
   1,015.80/1,401.81 = 550.05/x
3. Step 3: Cross multiply
   1,015.80x = 1,401.81 × 550.05
4. Step 4: Simplify right side
   1,015.80x = 771,072.42
5. Step 5: Solve for x
   x = 771,072.42/1,015.80
6. Step 6: Final answer
   x = 759.08