Finding the Third Proportional to 50,978 and 78,740

Step by Step Solution

1. Step 1: Write the proportion equation
   50,978 : 78,740 = 78,740 : x
2. Step 2: Convert to fraction form
   50,978/78,740 = 78,740/x
3. Step 3: Cross multiply
   50,978x = 78,740 × 78,740
4. Step 4: Simplify right side
   50,978x = 6,199,987,600
5. Step 5: Solve for x
   x = 6,199,987,600/50,978
6. Step 6: Final answer
   x = 121,620.85