Finding the Third Proportional to 9,720 and 20,477.50

Step by Step Solution

1. Step 1: Write the proportion equation
   9,720 : 20,477.50 = 20,477.50 : x
2. Step 2: Convert to fraction form
   9,720/20,477.50 = 20,477.50/x
3. Step 3: Cross multiply
   9,720x = 20,477.50 × 20,477.50
4. Step 4: Simplify right side
   9,720x = 419,327,846.27
5. Step 5: Solve for x
   x = 419,327,846.27/9,720
6. Step 6: Final answer
   x = 43,140.72