Finding the Fourth Proportional to 1,095.31, 1,643.42 and 478.70

Step by Step Solution

1. Step 1: Write the proportion equation
   1,095.31 : 1,643.42 = 478.70 : x
2. Step 2: Convert to fraction form
   1,095.31/1,643.42 = 478.70/x
3. Step 3: Cross multiply
   1,095.31x = 1,643.42 × 478.70
4. Step 4: Simplify right side
   1,095.31x = 786,705.15
5. Step 5: Solve for x
   x = 786,705.15/1,095.31
6. Step 6: Final answer
   x = 718.25