Finding the Third Proportional to 3,505.78 and 7,639.31

Step by Step Solution

1. Step 1: Write the proportion equation
   3,505.78 : 7,639.31 = 7,639.31 : x
2. Step 2: Convert to fraction form
   3,505.78/7,639.31 = 7,639.31/x
3. Step 3: Cross multiply
   3,505.78x = 7,639.31 × 7,639.31
4. Step 4: Simplify right side
   3,505.78x = 58,359,095.47
5. Step 5: Solve for x
   x = 58,359,095.47/3,505.78
6. Step 6: Final answer
   x = 16,646.53