Finding the Third Proportional to 356,691 and 521,910

Step by Step Solution

1. Step 1: Write the proportion equation
   356,691 : 521,910 = 521,910 : x
2. Step 2: Convert to fraction form
   356,691/521,910 = 521,910/x
3. Step 3: Cross multiply
   356,691x = 521,910 × 521,910
4. Step 4: Simplify right side
   356,691x = 272,390,048,100
5. Step 5: Solve for x
   x = 272,390,048,100/356,691
6. Step 6: Final answer
   x = 763,658.32