Finding the Third Proportional to 78,820 and 172,969

Step by Step Solution

1. Step 1: Write the proportion equation
   78,820 : 172,969 = 172,969 : x
2. Step 2: Convert to fraction form
   78,820/172,969 = 172,969/x
3. Step 3: Cross multiply
   78,820x = 172,969 × 172,969
4. Step 4: Simplify right side
   78,820x = 29,918,274,961
5. Step 5: Solve for x
   x = 29,918,274,961/78,820
6. Step 6: Final answer
   x = 379,577.20