Finding the Third Proportional to 638.72 and 1,368.56

Step by Step Solution

1. Step 1: Write the proportion equation
   638.72 : 1,368.56 = 1,368.56 : x
2. Step 2: Convert to fraction form
   638.72/1,368.56 = 1,368.56/x
3. Step 3: Cross multiply
   638.72x = 1,368.56 × 1,368.56
4. Step 4: Simplify right side
   638.72x = 1,872,963.32
5. Step 5: Solve for x
   x = 1,872,963.32/638.72
6. Step 6: Final answer
   x = 2,932.38