Finding the Third Proportional to 258,025.50 and 390,931.50

Step by Step Solution

1. Step 1: Write the proportion equation
   258,025.50 : 390,931.50 = 390,931.50 : x
2. Step 2: Convert to fraction form
   258,025.50/390,931.50 = 390,931.50/x
3. Step 3: Cross multiply
   258,025.50x = 390,931.50 × 390,931.50
4. Step 4: Simplify right side
   258,025.50x = 152,827,437,692.25
5. Step 5: Solve for x
   x = 152,827,437,692.25/258,025.50
6. Step 6: Final answer
   x = 592,295.87