Finding the Third Proportional to 385,271 and 511,209.50

Step by Step Solution

1. Step 1: Write the proportion equation
   385,271 : 511,209.50 = 511,209.50 : x
2. Step 2: Convert to fraction form
   385,271/511,209.50 = 511,209.50/x
3. Step 3: Cross multiply
   385,271x = 511,209.50 × 511,209.50
4. Step 4: Simplify right side
   385,271x = 261,335,152,890.25
5. Step 5: Solve for x
   x = 261,335,152,890.25/385,271
6. Step 6: Final answer
   x = 678,315.14