Finding the Fourth Proportional to 1,078.72, 1,618.32 and 429.52

Step by Step Solution

1. Step 1: Write the proportion equation
   1,078.72 : 1,618.32 = 429.52 : x
2. Step 2: Convert to fraction form
   1,078.72/1,618.32 = 429.52/x
3. Step 3: Cross multiply
   1,078.72x = 1,618.32 × 429.52
4. Step 4: Simplify right side
   1,078.72x = 695,100.81
5. Step 5: Solve for x
   x = 695,100.81/1,078.72
6. Step 6: Final answer
   x = 644.38