Finding the Third Proportional to 8,658 and 12,679.50

Step by Step Solution

1. Step 1: Write the proportion equation
   8,658 : 12,679.50 = 12,679.50 : x
2. Step 2: Convert to fraction form
   8,658/12,679.50 = 12,679.50/x
3. Step 3: Cross multiply
   8,658x = 12,679.50 × 12,679.50
4. Step 4: Simplify right side
   8,658x = 160,769,720.25
5. Step 5: Solve for x
   x = 160,769,720.25/8,658
6. Step 6: Final answer
   x = 18,568.92