Finding the Fourth Proportional to 1,078.91, 1,617.45 and 430.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,078.91 : 1,617.45 = 430.10 : x
2. Step 2: Convert to fraction form
   1,078.91/1,617.45 = 430.10/x
3. Step 3: Cross multiply
   1,078.91x = 1,617.45 × 430.10
4. Step 4: Simplify right side
   1,078.91x = 695,665.25
5. Step 5: Solve for x
   x = 695,665.25/1,078.91
6. Step 6: Final answer
   x = 644.79