Finding the Third Proportional to 123,678 and 199,134

Step by Step Solution

1. Step 1: Write the proportion equation
   123,678 : 199,134 = 199,134 : x
2. Step 2: Convert to fraction form
   123,678/199,134 = 199,134/x
3. Step 3: Cross multiply
   123,678x = 199,134 × 199,134
4. Step 4: Simplify right side
   123,678x = 39,654,349,956
5. Step 5: Solve for x
   x = 39,654,349,956/123,678
6. Step 6: Final answer
   x = 320,625.74