Finding the Third Proportional to 256,768.50 and 385,200

Step by Step Solution

1. Step 1: Write the proportion equation
   256,768.50 : 385,200 = 385,200 : x
2. Step 2: Convert to fraction form
   256,768.50/385,200 = 385,200/x
3. Step 3: Cross multiply
   256,768.50x = 385,200 × 385,200
4. Step 4: Simplify right side
   256,768.50x = 148,379,040,000
5. Step 5: Solve for x
   x = 148,379,040,000/256,768.50
6. Step 6: Final answer
   x = 577,870.88