Finding the Third Proportional to 128,520 and 200,980.50

Step by Step Solution

1. Step 1: Write the proportion equation
   128,520 : 200,980.50 = 200,980.50 : x
2. Step 2: Convert to fraction form
   128,520/200,980.50 = 200,980.50/x
3. Step 3: Cross multiply
   128,520x = 200,980.50 × 200,980.50
4. Step 4: Simplify right side
   128,520x = 40,393,161,380.25
5. Step 5: Solve for x
   x = 40,393,161,380.25/128,520
6. Step 6: Final answer
   x = 314,294.75