Finding the Third Proportional to 78,397 and 172,400.50

Step by Step Solution

1. Step 1: Write the proportion equation
   78,397 : 172,400.50 = 172,400.50 : x
2. Step 2: Convert to fraction form
   78,397/172,400.50 = 172,400.50/x
3. Step 3: Cross multiply
   78,397x = 172,400.50 × 172,400.50
4. Step 4: Simplify right side
   78,397x = 29,721,932,400.25
5. Step 5: Solve for x
   x = 29,721,932,400.25/78,397
6. Step 6: Final answer
   x = 379,120.79