Finding the Third Proportional to 259,684 and 391,235.50

Step by Step Solution

1. Step 1: Write the proportion equation
   259,684 : 391,235.50 = 391,235.50 : x
2. Step 2: Convert to fraction form
   259,684/391,235.50 = 391,235.50/x
3. Step 3: Cross multiply
   259,684x = 391,235.50 × 391,235.50
4. Step 4: Simplify right side
   259,684x = 153,065,216,460.25
5. Step 5: Solve for x
   x = 153,065,216,460.25/259,684
6. Step 6: Final answer
   x = 589,428.75