Finding the Third Proportional to 12,780.50 and 19,740.75

Step by Step Solution

1. Step 1: Write the proportion equation
   12,780.50 : 19,740.75 = 19,740.75 : x
2. Step 2: Convert to fraction form
   12,780.50/19,740.75 = 19,740.75/x
3. Step 3: Cross multiply
   12,780.50x = 19,740.75 × 19,740.75
4. Step 4: Simplify right side
   12,780.50x = 389,697,210.56
5. Step 5: Solve for x
   x = 389,697,210.56/12,780.50
6. Step 6: Final answer
   x = 30,491.55