Finding the Third Proportional to 128,580 and 280,008

Step by Step Solution

1. Step 1: Write the proportion equation
   128,580 : 280,008 = 280,008 : x
2. Step 2: Convert to fraction form
   128,580/280,008 = 280,008/x
3. Step 3: Cross multiply
   128,580x = 280,008 × 280,008
4. Step 4: Simplify right side
   128,580x = 78,404,480,064
5. Step 5: Solve for x
   x = 78,404,480,064/128,580
6. Step 6: Final answer
   x = 609,771.97