Finding the Third Proportional to 3,985.45 and 8,728.59

Step by Step Solution

1. Step 1: Write the proportion equation
   3,985.45 : 8,728.59 = 8,728.59 : x
2. Step 2: Convert to fraction form
   3,985.45/8,728.59 = 8,728.59/x
3. Step 3: Cross multiply
   3,985.45x = 8,728.59 × 8,728.59
4. Step 4: Simplify right side
   3,985.45x = 76,188,348.85
5. Step 5: Solve for x
   x = 76,188,348.85/3,985.45
6. Step 6: Final answer
   x = 19,116.61