Finding the Third Proportional to 120,621 and 257,272.50

Step by Step Solution

1. Step 1: Write the proportion equation
   120,621 : 257,272.50 = 257,272.50 : x
2. Step 2: Convert to fraction form
   120,621/257,272.50 = 257,272.50/x
3. Step 3: Cross multiply
   120,621x = 257,272.50 × 257,272.50
4. Step 4: Simplify right side
   120,621x = 66,189,139,256.25
5. Step 5: Solve for x
   x = 66,189,139,256.25/120,621
6. Step 6: Final answer
   x = 548,736.45