Finding the Third Proportional to 51,131.50 and 78,481.75

Step by Step Solution

1. Step 1: Write the proportion equation
   51,131.50 : 78,481.75 = 78,481.75 : x
2. Step 2: Convert to fraction form
   51,131.50/78,481.75 = 78,481.75/x
3. Step 3: Cross multiply
   51,131.50x = 78,481.75 × 78,481.75
4. Step 4: Simplify right side
   51,131.50x = 6,159,385,083.06
5. Step 5: Solve for x
   x = 6,159,385,083.06/51,131.50
6. Step 6: Final answer
   x = 120,461.65