Finding the Third Proportional to 3,990.52 and 8,580.94

Step by Step Solution

1. Step 1: Write the proportion equation
   3,990.52 : 8,580.94 = 8,580.94 : x
2. Step 2: Convert to fraction form
   3,990.52/8,580.94 = 8,580.94/x
3. Step 3: Cross multiply
   3,990.52x = 8,580.94 × 8,580.94
4. Step 4: Simplify right side
   3,990.52x = 73,632,488.38
5. Step 5: Solve for x
   x = 73,632,488.38/3,990.52
6. Step 6: Final answer
   x = 18,451.87