Finding the Third Proportional to 128,200.50 and 199,020.38

Step by Step Solution

1. Step 1: Write the proportion equation
   128,200.50 : 199,020.38 = 199,020.38 : x
2. Step 2: Convert to fraction form
   128,200.50/199,020.38 = 199,020.38/x
3. Step 3: Cross multiply
   128,200.50x = 199,020.38 × 199,020.38
4. Step 4: Simplify right side
   128,200.50x = 39,609,109,665.14
5. Step 5: Solve for x
   x = 39,609,109,665.14/128,200.50
6. Step 6: Final answer
   x = 308,962.21