Finding the Third Proportional to 120,322.50 and 256,128

Step by Step Solution

1. Step 1: Write the proportion equation
   120,322.50 : 256,128 = 256,128 : x
2. Step 2: Convert to fraction form
   120,322.50/256,128 = 256,128/x
3. Step 3: Cross multiply
   120,322.50x = 256,128 × 256,128
4. Step 4: Simplify right side
   120,322.50x = 65,601,552,384
5. Step 5: Solve for x
   x = 65,601,552,384/120,322.50
6. Step 6: Final answer
   x = 545,214.34