Finding the Third Proportional to 129,978 and 279,300

Step by Step Solution

1. Step 1: Write the proportion equation
   129,978 : 279,300 = 279,300 : x
2. Step 2: Convert to fraction form
   129,978/279,300 = 279,300/x
3. Step 3: Cross multiply
   129,978x = 279,300 × 279,300
4. Step 4: Simplify right side
   129,978x = 78,008,490,000
5. Step 5: Solve for x
   x = 78,008,490,000/129,978
6. Step 6: Final answer
   x = 600,166.87