Finding the Third Proportional to 31,390.50 and 68,109

Step by Step Solution

1. Step 1: Write the proportion equation
   31,390.50 : 68,109 = 68,109 : x
2. Step 2: Convert to fraction form
   31,390.50/68,109 = 68,109/x
3. Step 3: Cross multiply
   31,390.50x = 68,109 × 68,109
4. Step 4: Simplify right side
   31,390.50x = 4,638,835,881
5. Step 5: Solve for x
   x = 4,638,835,881/31,390.50
6. Step 6: Final answer
   x = 147,778.34