Finding the Third Proportional to 66,611 and 139,380

Step by Step Solution

1. Step 1: Write the proportion equation
   66,611 : 139,380 = 139,380 : x
2. Step 2: Convert to fraction form
   66,611/139,380 = 139,380/x
3. Step 3: Cross multiply
   66,611x = 139,380 × 139,380
4. Step 4: Simplify right side
   66,611x = 19,426,784,400
5. Step 5: Solve for x
   x = 19,426,784,400/66,611
6. Step 6: Final answer
   x = 291,645.29