Finding the Fourth Proportional to 1,020.88, 1,408.72 and 627.92

Step by Step Solution

1. Step 1: Write the proportion equation
   1,020.88 : 1,408.72 = 627.92 : x
2. Step 2: Convert to fraction form
   1,020.88/1,408.72 = 627.92/x
3. Step 3: Cross multiply
   1,020.88x = 1,408.72 × 627.92
4. Step 4: Simplify right side
   1,020.88x = 884,563.46
5. Step 5: Solve for x
   x = 884,563.46/1,020.88
6. Step 6: Final answer
   x = 866.47