Finding the Fourth Proportional to 1,020.81, 1,408.73 and 555.06

Step by Step Solution

1. Step 1: Write the proportion equation
   1,020.81 : 1,408.73 = 555.06 : x
2. Step 2: Convert to fraction form
   1,020.81/1,408.73 = 555.06/x
3. Step 3: Cross multiply
   1,020.81x = 1,408.73 × 555.06
4. Step 4: Simplify right side
   1,020.81x = 781,929.67
5. Step 5: Solve for x
   x = 781,929.67/1,020.81
6. Step 6: Final answer
   x = 765.99