Finding the Third Proportional to 59,978 and 129,172

Step by Step Solution

1. Step 1: Write the proportion equation
   59,978 : 129,172 = 129,172 : x
2. Step 2: Convert to fraction form
   59,978/129,172 = 129,172/x
3. Step 3: Cross multiply
   59,978x = 129,172 × 129,172
4. Step 4: Simplify right side
   59,978x = 16,685,405,584
5. Step 5: Solve for x
   x = 16,685,405,584/59,978
6. Step 6: Final answer
   x = 278,192.10