Finding the Third Proportional to 257,988 and 390,877.50

Step by Step Solution

1. Step 1: Write the proportion equation
   257,988 : 390,877.50 = 390,877.50 : x
2. Step 2: Convert to fraction form
   257,988/390,877.50 = 390,877.50/x
3. Step 3: Cross multiply
   257,988x = 390,877.50 × 390,877.50
4. Step 4: Simplify right side
   257,988x = 152,785,220,006.25
5. Step 5: Solve for x
   x = 152,785,220,006.25/257,988
6. Step 6: Final answer
   x = 592,218.32