Finding the Third Proportional to 31,421 and 68,369.50

Step by Step Solution

1. Step 1: Write the proportion equation
   31,421 : 68,369.50 = 68,369.50 : x
2. Step 2: Convert to fraction form
   31,421/68,369.50 = 68,369.50/x
3. Step 3: Cross multiply
   31,421x = 68,369.50 × 68,369.50
4. Step 4: Simplify right side
   31,421x = 4,674,388,530.25
5. Step 5: Solve for x
   x = 4,674,388,530.25/31,421
6. Step 6: Final answer
   x = 148,766.38