Finding the Third Proportional to 30,679.50 and 65,728.50

Step by Step Solution

1. Step 1: Write the proportion equation
   30,679.50 : 65,728.50 = 65,728.50 : x
2. Step 2: Convert to fraction form
   30,679.50/65,728.50 = 65,728.50/x
3. Step 3: Cross multiply
   30,679.50x = 65,728.50 × 65,728.50
4. Step 4: Simplify right side
   30,679.50x = 4,320,235,712.25
5. Step 5: Solve for x
   x = 4,320,235,712.25/30,679.50
6. Step 6: Final answer
   x = 140,818.32