Finding the Fourth Proportional to 1,020.82, 1,408.72 and 555.07

Step by Step Solution

1. Step 1: Write the proportion equation
   1,020.82 : 1,408.72 = 555.07 : x
2. Step 2: Convert to fraction form
   1,020.82/1,408.72 = 555.07/x
3. Step 3: Cross multiply
   1,020.82x = 1,408.72 × 555.07
4. Step 4: Simplify right side
   1,020.82x = 781,931.17
5. Step 5: Solve for x
   x = 781,931.17/1,020.82
6. Step 6: Final answer
   x = 765.99