Finding the Third Proportional to 8,172.56 and 12,578.63

Step by Step Solution

1. Step 1: Write the proportion equation
   8,172.56 : 12,578.63 = 12,578.63 : x
2. Step 2: Convert to fraction form
   8,172.56/12,578.63 = 12,578.63/x
3. Step 3: Cross multiply
   8,172.56x = 12,578.63 × 12,578.63
4. Step 4: Simplify right side
   8,172.56x = 158,221,806.89
5. Step 5: Solve for x
   x = 158,221,806.89/8,172.56
6. Step 6: Final answer
   x = 19,360.12