Finding the Third Proportional to 8,419.50 and 12,980.25

Step by Step Solution

1. Step 1: Write the proportion equation
   8,419.50 : 12,980.25 = 12,980.25 : x
2. Step 2: Convert to fraction form
   8,419.50/12,980.25 = 12,980.25/x
3. Step 3: Cross multiply
   8,419.50x = 12,980.25 × 12,980.25
4. Step 4: Simplify right side
   8,419.50x = 168,486,890.06
5. Step 5: Solve for x
   x = 168,486,890.06/8,419.50
6. Step 6: Final answer
   x = 20,011.51