Finding the Third Proportional to 8,313.75 and 12,856.50

Step by Step Solution

1. Step 1: Write the proportion equation
   8,313.75 : 12,856.50 = 12,856.50 : x
2. Step 2: Convert to fraction form
   8,313.75/12,856.50 = 12,856.50/x
3. Step 3: Cross multiply
   8,313.75x = 12,856.50 × 12,856.50
4. Step 4: Simplify right side
   8,313.75x = 165,289,592.25
5. Step 5: Solve for x
   x = 165,289,592.25/8,313.75
6. Step 6: Final answer
   x = 19,881.47