Finding the Fourth Proportional to 1,078.31, 1,487.53 and 705.30

Step by Step Solution

1. Step 1: Write the proportion equation
   1,078.31 : 1,487.53 = 705.30 : x
2. Step 2: Convert to fraction form
   1,078.31/1,487.53 = 705.30/x
3. Step 3: Cross multiply
   1,078.31x = 1,487.53 × 705.30
4. Step 4: Simplify right side
   1,078.31x = 1,049,153.15
5. Step 5: Solve for x
   x = 1,049,153.15/1,078.31
6. Step 6: Final answer
   x = 972.97