Finding the Third Proportional to 12,780 and 27,991.50

Step by Step Solution

1. Step 1: Write the proportion equation
   12,780 : 27,991.50 = 27,991.50 : x
2. Step 2: Convert to fraction form
   12,780/27,991.50 = 27,991.50/x
3. Step 3: Cross multiply
   12,780x = 27,991.50 × 27,991.50
4. Step 4: Simplify right side
   12,780x = 783,524,072.25
5. Step 5: Solve for x
   x = 783,524,072.25/12,780
6. Step 6: Final answer
   x = 61,308.61