Finding the Third Proportional to 639.94 and 1,068.38

Step by Step Solution

1. Step 1: Write the proportion equation
   639.94 : 1,068.38 = 1,068.38 : x
2. Step 2: Convert to fraction form
   639.94/1,068.38 = 1,068.38/x
3. Step 3: Cross multiply
   639.94x = 1,068.38 × 1,068.38
4. Step 4: Simplify right side
   639.94x = 1,141,425.14
5. Step 5: Solve for x
   x = 1,141,425.14/639.94
6. Step 6: Final answer
   x = 1,783.65