Finding the Third Proportional to 171,788 and 256,886

Step by Step Solution

1. Step 1: Write the proportion equation
   171,788 : 256,886 = 256,886 : x
2. Step 2: Convert to fraction form
   171,788/256,886 = 256,886/x
3. Step 3: Cross multiply
   171,788x = 256,886 × 256,886
4. Step 4: Simplify right side
   171,788x = 65,990,416,996
5. Step 5: Solve for x
   x = 65,990,416,996/171,788
6. Step 6: Final answer
   x = 384,138.69