Finding the Third Proportional to 3,872.81 and 8,402.91

Step by Step Solution

1. Step 1: Write the proportion equation
   3,872.81 : 8,402.91 = 8,402.91 : x
2. Step 2: Convert to fraction form
   3,872.81/8,402.91 = 8,402.91/x
3. Step 3: Cross multiply
   3,872.81x = 8,402.91 × 8,402.91
4. Step 4: Simplify right side
   3,872.81x = 70,608,833.45
5. Step 5: Solve for x
   x = 70,608,833.45/3,872.81
6. Step 6: Final answer
   x = 18,231.93