Finding the Third Proportional to 78,798 and 172,905

Step by Step Solution

1. Step 1: Write the proportion equation
   78,798 : 172,905 = 172,905 : x
2. Step 2: Convert to fraction form
   78,798/172,905 = 172,905/x
3. Step 3: Cross multiply
   78,798x = 172,905 × 172,905
4. Step 4: Simplify right side
   78,798x = 29,896,139,025
5. Step 5: Solve for x
   x = 29,896,139,025/78,798
6. Step 6: Final answer
   x = 379,402.26