Finding the Third Proportional to 78,777.56 and 172,861.59

Step by Step Solution

1. Step 1: Write the proportion equation
   78,777.56 : 172,861.59 = 172,861.59 : x
2. Step 2: Convert to fraction form
   78,777.56/172,861.59 = 172,861.59/x
3. Step 3: Cross multiply
   78,777.56x = 172,861.59 × 172,861.59
4. Step 4: Simplify right side
   78,777.56x = 29,881,130,593.79
5. Step 5: Solve for x
   x = 29,881,130,593.79/78,777.56
6. Step 6: Final answer
   x = 379,310.17