Finding the Third Proportional to 31,640 and 64,860

Step by Step Solution

1. Step 1: Write the proportion equation
   31,640 : 64,860 = 64,860 : x
2. Step 2: Convert to fraction form
   31,640/64,860 = 64,860/x
3. Step 3: Cross multiply
   31,640x = 64,860 × 64,860
4. Step 4: Simplify right side
   31,640x = 4,206,819,600
5. Step 5: Solve for x
   x = 4,206,819,600/31,640
6. Step 6: Final answer
   x = 132,958.90