Finding the Third Proportional to 13,720.50 and 20,499.75

Step by Step Solution

1. Step 1: Write the proportion equation
   13,720.50 : 20,499.75 = 20,499.75 : x
2. Step 2: Convert to fraction form
   13,720.50/20,499.75 = 20,499.75/x
3. Step 3: Cross multiply
   13,720.50x = 20,499.75 × 20,499.75
4. Step 4: Simplify right side
   13,720.50x = 420,239,750.06
5. Step 5: Solve for x
   x = 420,239,750.06/13,720.50
6. Step 6: Final answer
   x = 30,628.60