Finding the Third Proportional to 139,431 and 215,442

Step by Step Solution

1. Step 1: Write the proportion equation
   139,431 : 215,442 = 215,442 : x
2. Step 2: Convert to fraction form
   139,431/215,442 = 215,442/x
3. Step 3: Cross multiply
   139,431x = 215,442 × 215,442
4. Step 4: Simplify right side
   139,431x = 46,415,255,364
5. Step 5: Solve for x
   x = 46,415,255,364/139,431
6. Step 6: Final answer
   x = 332,890.50