Finding the Third Proportional to 8,471 and 12,815.50

Step by Step Solution

1. Step 1: Write the proportion equation
   8,471 : 12,815.50 = 12,815.50 : x
2. Step 2: Convert to fraction form
   8,471/12,815.50 = 12,815.50/x
3. Step 3: Cross multiply
   8,471x = 12,815.50 × 12,815.50
4. Step 4: Simplify right side
   8,471x = 164,237,040.25
5. Step 5: Solve for x
   x = 164,237,040.25/8,471
6. Step 6: Final answer
   x = 19,388.15