Finding the Third Proportional to 13,688.25 and 19,780.50

Step by Step Solution

1. Step 1: Write the proportion equation
   13,688.25 : 19,780.50 = 19,780.50 : x
2. Step 2: Convert to fraction form
   13,688.25/19,780.50 = 19,780.50/x
3. Step 3: Cross multiply
   13,688.25x = 19,780.50 × 19,780.50
4. Step 4: Simplify right side
   13,688.25x = 391,268,180.25
5. Step 5: Solve for x
   x = 391,268,180.25/13,688.25
6. Step 6: Final answer
   x = 28,584.24