Finding the Third Proportional to 158,390 and 329,840

Step by Step Solution

1. Step 1: Write the proportion equation
   158,390 : 329,840 = 329,840 : x
2. Step 2: Convert to fraction form
   158,390/329,840 = 329,840/x
3. Step 3: Cross multiply
   158,390x = 329,840 × 329,840
4. Step 4: Simplify right side
   158,390x = 108,794,425,600
5. Step 5: Solve for x
   x = 108,794,425,600/158,390
6. Step 6: Final answer
   x = 686,876.86