Finding the Third Proportional to 31,915.50 and 66,456

Step by Step Solution

1. Step 1: Write the proportion equation
   31,915.50 : 66,456 = 66,456 : x
2. Step 2: Convert to fraction form
   31,915.50/66,456 = 66,456/x
3. Step 3: Cross multiply
   31,915.50x = 66,456 × 66,456
4. Step 4: Simplify right side
   31,915.50x = 4,416,399,936
5. Step 5: Solve for x
   x = 4,416,399,936/31,915.50
6. Step 6: Final answer
   x = 138,377.90