Finding the Third Proportional to 171,789 and 256,890

Step by Step Solution

1. Step 1: Write the proportion equation
   171,789 : 256,890 = 256,890 : x
2. Step 2: Convert to fraction form
   171,789/256,890 = 256,890/x
3. Step 3: Cross multiply
   171,789x = 256,890 × 256,890
4. Step 4: Simplify right side
   171,789x = 65,992,472,100
5. Step 5: Solve for x
   x = 65,992,472,100/171,789
6. Step 6: Final answer
   x = 384,148.42