Finding the Third Proportional to 390,426 and 530,334

Step by Step Solution

1. Step 1: Write the proportion equation
   390,426 : 530,334 = 530,334 : x
2. Step 2: Convert to fraction form
   390,426/530,334 = 530,334/x
3. Step 3: Cross multiply
   390,426x = 530,334 × 530,334
4. Step 4: Simplify right side
   390,426x = 281,254,151,556
5. Step 5: Solve for x
   x = 281,254,151,556/390,426
6. Step 6: Final answer
   x = 720,377.62