Finding the Third Proportional to 128,176.50 and 280,476

Step by Step Solution

1. Step 1: Write the proportion equation
   128,176.50 : 280,476 = 280,476 : x
2. Step 2: Convert to fraction form
   128,176.50/280,476 = 280,476/x
3. Step 3: Cross multiply
   128,176.50x = 280,476 × 280,476
4. Step 4: Simplify right side
   128,176.50x = 78,666,786,576
5. Step 5: Solve for x
   x = 78,666,786,576/128,176.50
6. Step 6: Final answer
   x = 613,737.98