Finding the Third Proportional to 8,436.66 and 12,985.31

Step by Step Solution

1. Step 1: Write the proportion equation
   8,436.66 : 12,985.31 = 12,985.31 : x
2. Step 2: Convert to fraction form
   8,436.66/12,985.31 = 12,985.31/x
3. Step 3: Cross multiply
   8,436.66x = 12,985.31 × 12,985.31
4. Step 4: Simplify right side
   8,436.66x = 168,618,340.72
5. Step 5: Solve for x
   x = 168,618,340.72/8,436.66
6. Step 6: Final answer
   x = 19,986.39