Finding the Third Proportional to 51,806 and 78,721.50

Step by Step Solution

1. Step 1: Write the proportion equation
   51,806 : 78,721.50 = 78,721.50 : x
2. Step 2: Convert to fraction form
   51,806/78,721.50 = 78,721.50/x
3. Step 3: Cross multiply
   51,806x = 78,721.50 × 78,721.50
4. Step 4: Simplify right side
   51,806x = 6,197,074,562.25
5. Step 5: Solve for x
   x = 6,197,074,562.25/51,806
6. Step 6: Final answer
   x = 119,620.79