Finding the Third Proportional to 258,047 and 390,960

Step by Step Solution

1. Step 1: Write the proportion equation
   258,047 : 390,960 = 390,960 : x
2. Step 2: Convert to fraction form
   258,047/390,960 = 390,960/x
3. Step 3: Cross multiply
   258,047x = 390,960 × 390,960
4. Step 4: Simplify right side
   258,047x = 152,849,721,600
5. Step 5: Solve for x
   x = 152,849,721,600/258,047
6. Step 6: Final answer
   x = 592,332.88