Finding the Third Proportional to 8,424 and 12,586.50

Step by Step Solution

1. Step 1: Write the proportion equation
   8,424 : 12,586.50 = 12,586.50 : x
2. Step 2: Convert to fraction form
   8,424/12,586.50 = 12,586.50/x
3. Step 3: Cross multiply
   8,424x = 12,586.50 × 12,586.50
4. Step 4: Simplify right side
   8,424x = 158,419,982.25
5. Step 5: Solve for x
   x = 158,419,982.25/8,424
6. Step 6: Final answer
   x = 18,805.79