Finding the Third Proportional to 78,654 and 172,860

Step by Step Solution

1. Step 1: Write the proportion equation
   78,654 : 172,860 = 172,860 : x
2. Step 2: Convert to fraction form
   78,654/172,860 = 172,860/x
3. Step 3: Cross multiply
   78,654x = 172,860 × 172,860
4. Step 4: Simplify right side
   78,654x = 29,880,579,600
5. Step 5: Solve for x
   x = 29,880,579,600/78,654
6. Step 6: Final answer
   x = 379,899.05