Finding the Third Proportional to 643.69 and 1,354.31

Step by Step Solution

1. Step 1: Write the proportion equation
   643.69 : 1,354.31 = 1,354.31 : x
2. Step 2: Convert to fraction form
   643.69/1,354.31 = 1,354.31/x
3. Step 3: Cross multiply
   643.69x = 1,354.31 × 1,354.31
4. Step 4: Simplify right side
   643.69x = 1,834,162.35
5. Step 5: Solve for x
   x = 1,834,162.35/643.69
6. Step 6: Final answer
   x = 2,849.46