Finding the Third Proportional to 120,861.50 and 256,131

Step by Step Solution

1. Step 1: Write the proportion equation
   120,861.50 : 256,131 = 256,131 : x
2. Step 2: Convert to fraction form
   120,861.50/256,131 = 256,131/x
3. Step 3: Cross multiply
   120,861.50x = 256,131 × 256,131
4. Step 4: Simplify right side
   120,861.50x = 65,603,089,161
5. Step 5: Solve for x
   x = 65,603,089,161/120,861.50
6. Step 6: Final answer
   x = 542,795.59