Finding the Third Proportional to 78,386 and 172,380

Step by Step Solution

1. Step 1: Write the proportion equation
   78,386 : 172,380 = 172,380 : x
2. Step 2: Convert to fraction form
   78,386/172,380 = 172,380/x
3. Step 3: Cross multiply
   78,386x = 172,380 × 172,380
4. Step 4: Simplify right side
   78,386x = 29,714,864,400
5. Step 5: Solve for x
   x = 29,714,864,400/78,386
6. Step 6: Final answer
   x = 379,083.82