Finding the Third Proportional to 390,070 and 582,530

Step by Step Solution

1. Step 1: Write the proportion equation
   390,070 : 582,530 = 582,530 : x
2. Step 2: Convert to fraction form
   390,070/582,530 = 582,530/x
3. Step 3: Cross multiply
   390,070x = 582,530 × 582,530
4. Step 4: Simplify right side
   390,070x = 339,341,200,900
5. Step 5: Solve for x
   x = 339,341,200,900/390,070
6. Step 6: Final answer
   x = 869,949.50