Finding the Third Proportional to 128,876 and 279,892

Step by Step Solution

1. Step 1: Write the proportion equation
   128,876 : 279,892 = 279,892 : x
2. Step 2: Convert to fraction form
   128,876/279,892 = 279,892/x
3. Step 3: Cross multiply
   128,876x = 279,892 × 279,892
4. Step 4: Simplify right side
   128,876x = 78,339,531,664
5. Step 5: Solve for x
   x = 78,339,531,664/128,876
6. Step 6: Final answer
   x = 607,867.50