Finding the Third Proportional to 161,678 and 355,139

Step by Step Solution

1. Step 1: Write the proportion equation
   161,678 : 355,139 = 355,139 : x
2. Step 2: Convert to fraction form
   161,678/355,139 = 355,139/x
3. Step 3: Cross multiply
   161,678x = 355,139 × 355,139
4. Step 4: Simplify right side
   161,678x = 126,123,709,321
5. Step 5: Solve for x
   x = 126,123,709,321/161,678
6. Step 6: Final answer
   x = 780,091.97