Finding the Third Proportional to 258,114 and 391,056

Step by Step Solution

1. Step 1: Write the proportion equation
   258,114 : 391,056 = 391,056 : x
2. Step 2: Convert to fraction form
   258,114/391,056 = 391,056/x
3. Step 3: Cross multiply
   258,114x = 391,056 × 391,056
4. Step 4: Simplify right side
   258,114x = 152,924,795,136
5. Step 5: Solve for x
   x = 152,924,795,136/258,114
6. Step 6: Final answer
   x = 592,469.98