Finding the Third Proportional to 261,423 and 391,054.50

Step by Step Solution

1. Step 1: Write the proportion equation
   261,423 : 391,054.50 = 391,054.50 : x
2. Step 2: Convert to fraction form
   261,423/391,054.50 = 391,054.50/x
3. Step 3: Cross multiply
   261,423x = 391,054.50 × 391,054.50
4. Step 4: Simplify right side
   261,423x = 152,923,621,970.25
5. Step 5: Solve for x
   x = 152,923,621,970.25/261,423
6. Step 6: Final answer
   x = 584,966.21