Finding the Third Proportional to 258,123 and 391,069.50

Step by Step Solution

1. Step 1: Write the proportion equation
   258,123 : 391,069.50 = 391,069.50 : x
2. Step 2: Convert to fraction form
   258,123/391,069.50 = 391,069.50/x
3. Step 3: Cross multiply
   258,123x = 391,069.50 × 391,069.50
4. Step 4: Simplify right side
   258,123x = 152,935,353,830.25
5. Step 5: Solve for x
   x = 152,935,353,830.25/258,123
6. Step 6: Final answer
   x = 592,490.22