Finding the Third Proportional to 660.81 and 1,439.31

Step by Step Solution

1. Step 1: Write the proportion equation
   660.81 : 1,439.31 = 1,439.31 : x
2. Step 2: Convert to fraction form
   660.81/1,439.31 = 1,439.31/x
3. Step 3: Cross multiply
   660.81x = 1,439.31 × 1,439.31
4. Step 4: Simplify right side
   660.81x = 2,071,620.47
5. Step 5: Solve for x
   x = 2,071,620.47/660.81
6. Step 6: Final answer
   x = 3,134.96