Finding the Fourth Proportional to 1,020.56, 1,408.30 and 622.17

Step by Step Solution

1. Step 1: Write the proportion equation
   1,020.56 : 1,408.30 = 622.17 : x
2. Step 2: Convert to fraction form
   1,020.56/1,408.30 = 622.17/x
3. Step 3: Cross multiply
   1,020.56x = 1,408.30 × 622.17
4. Step 4: Simplify right side
   1,020.56x = 876,200.46
5. Step 5: Solve for x
   x = 876,200.46/1,020.56
6. Step 6: Final answer
   x = 858.55