Finding the Fourth Proportional to 1,078.69, 1,619.25 and 429.88

Step by Step Solution

1. Step 1: Write the proportion equation
   1,078.69 : 1,619.25 = 429.88 : x
2. Step 2: Convert to fraction form
   1,078.69/1,619.25 = 429.88/x
3. Step 3: Cross multiply
   1,078.69x = 1,619.25 × 429.88
4. Step 4: Simplify right side
   1,078.69x = 696,083.19
5. Step 5: Solve for x
   x = 696,083.19/1,078.69
6. Step 6: Final answer
   x = 645.30