Finding the Third Proportional to 128,958 and 280,069.50

Step by Step Solution

1. Step 1: Write the proportion equation
   128,958 : 280,069.50 = 280,069.50 : x
2. Step 2: Convert to fraction form
   128,958/280,069.50 = 280,069.50/x
3. Step 3: Cross multiply
   128,958x = 280,069.50 × 280,069.50
4. Step 4: Simplify right side
   128,958x = 78,438,924,830.25
5. Step 5: Solve for x
   x = 78,438,924,830.25/128,958
6. Step 6: Final answer
   x = 608,251.72