Finding the Third Proportional to 51,155.50 and 78,920

Step by Step Solution

1. Step 1: Write the proportion equation
   51,155.50 : 78,920 = 78,920 : x
2. Step 2: Convert to fraction form
   51,155.50/78,920 = 78,920/x
3. Step 3: Cross multiply
   51,155.50x = 78,920 × 78,920
4. Step 4: Simplify right side
   51,155.50x = 6,228,366,400
5. Step 5: Solve for x
   x = 6,228,366,400/51,155.50
6. Step 6: Final answer
   x = 121,753.60