Finding the Third Proportional to 721.69 and 1,089.56

Step by Step Solution

1. Step 1: Write the proportion equation
   721.69 : 1,089.56 = 1,089.56 : x
2. Step 2: Convert to fraction form
   721.69/1,089.56 = 1,089.56/x
3. Step 3: Cross multiply
   721.69x = 1,089.56 × 1,089.56
4. Step 4: Simplify right side
   721.69x = 1,187,146.44
5. Step 5: Solve for x
   x = 1,187,146.44/721.69
6. Step 6: Final answer
   x = 1,644.96