Finding the Third Proportional to 50,715 and 78,840

Step by Step Solution

1. Step 1: Write the proportion equation
   50,715 : 78,840 = 78,840 : x
2. Step 2: Convert to fraction form
   50,715/78,840 = 78,840/x
3. Step 3: Cross multiply
   50,715x = 78,840 × 78,840
4. Step 4: Simplify right side
   50,715x = 6,215,745,600
5. Step 5: Solve for x
   x = 6,215,745,600/50,715
6. Step 6: Final answer
   x = 122,562.27