Finding the Third Proportional to 128,338 and 309,180

Step by Step Solution

1. Step 1: Write the proportion equation
   128,338 : 309,180 = 309,180 : x
2. Step 2: Convert to fraction form
   128,338/309,180 = 309,180/x
3. Step 3: Cross multiply
   128,338x = 309,180 × 309,180
4. Step 4: Simplify right side
   128,338x = 95,592,272,400
5. Step 5: Solve for x
   x = 95,592,272,400/128,338
6. Step 6: Final answer
   x = 744,847.76