Finding the Fourth Proportional to 1,078.56, 1,618.50 and 429.18

Step by Step Solution

1. Step 1: Write the proportion equation
   1,078.56 : 1,618.50 = 429.18 : x
2. Step 2: Convert to fraction form
   1,078.56/1,618.50 = 429.18/x
3. Step 3: Cross multiply
   1,078.56x = 1,618.50 × 429.18
4. Step 4: Simplify right side
   1,078.56x = 694,627.83
5. Step 5: Solve for x
   x = 694,627.83/1,078.56
6. Step 6: Final answer
   x = 644.03