Finding the Third Proportional to 258,120 and 391,065

Step by Step Solution

1. Step 1: Write the proportion equation
   258,120 : 391,065 = 391,065 : x
2. Step 2: Convert to fraction form
   258,120/391,065 = 391,065/x
3. Step 3: Cross multiply
   258,120x = 391,065 × 391,065
4. Step 4: Simplify right side
   258,120x = 152,931,834,225
5. Step 5: Solve for x
   x = 152,931,834,225/258,120
6. Step 6: Final answer
   x = 592,483.47