Finding the Third Proportional to 8,557 and 12,778.50

Step by Step Solution

1. Step 1: Write the proportion equation
   8,557 : 12,778.50 = 12,778.50 : x
2. Step 2: Convert to fraction form
   8,557/12,778.50 = 12,778.50/x
3. Step 3: Cross multiply
   8,557x = 12,778.50 × 12,778.50
4. Step 4: Simplify right side
   8,557x = 163,290,062.25
5. Step 5: Solve for x
   x = 163,290,062.25/8,557
6. Step 6: Final answer
   x = 19,082.63