Finding the Third Proportional to 128,305 and 309,098.50

Step by Step Solution

1. Step 1: Write the proportion equation
   128,305 : 309,098.50 = 309,098.50 : x
2. Step 2: Convert to fraction form
   128,305/309,098.50 = 309,098.50/x
3. Step 3: Cross multiply
   128,305x = 309,098.50 × 309,098.50
4. Step 4: Simplify right side
   128,305x = 95,541,882,702.25
5. Step 5: Solve for x
   x = 95,541,882,702.25/128,305
6. Step 6: Final answer
   x = 744,646.61