Finding the Third Proportional to 3,658.50 and 8,422.31

Step by Step Solution

1. Step 1: Write the proportion equation
   3,658.50 : 8,422.31 = 8,422.31 : x
2. Step 2: Convert to fraction form
   3,658.50/8,422.31 = 8,422.31/x
3. Step 3: Cross multiply
   3,658.50x = 8,422.31 × 8,422.31
4. Step 4: Simplify right side
   3,658.50x = 70,935,347.85
5. Step 5: Solve for x
   x = 70,935,347.85/3,658.50
6. Step 6: Final answer
   x = 19,389.19