Finding the Third Proportional to 128,298 and 199,141.50

Step by Step Solution

1. Step 1: Write the proportion equation
   128,298 : 199,141.50 = 199,141.50 : x
2. Step 2: Convert to fraction form
   128,298/199,141.50 = 199,141.50/x
3. Step 3: Cross multiply
   128,298x = 199,141.50 × 199,141.50
4. Step 4: Simplify right side
   128,298x = 39,657,337,022.25
5. Step 5: Solve for x
   x = 39,657,337,022.25/128,298
6. Step 6: Final answer
   x = 309,103.31