Finding the Third Proportional to 83,978 and 128,859

Step by Step Solution

1. Step 1: Write the proportion equation
   83,978 : 128,859 = 128,859 : x
2. Step 2: Convert to fraction form
   83,978/128,859 = 128,859/x
3. Step 3: Cross multiply
   83,978x = 128,859 × 128,859
4. Step 4: Simplify right side
   83,978x = 16,604,641,881
5. Step 5: Solve for x
   x = 16,604,641,881/83,978
6. Step 6: Final answer
   x = 197,726.09