Finding the Fourth Proportional to 1,020.37, 1,408.15 and 554.63

Step by Step Solution

1. Step 1: Write the proportion equation
   1,020.37 : 1,408.15 = 554.63 : x
2. Step 2: Convert to fraction form
   1,020.37/1,408.15 = 554.63/x
3. Step 3: Cross multiply
   1,020.37x = 1,408.15 × 554.63
4. Step 4: Simplify right side
   1,020.37x = 780,999.46
5. Step 5: Solve for x
   x = 780,999.46/1,020.37
6. Step 6: Final answer
   x = 765.41