Finding the Third Proportional to 78,815 and 172,942

Step by Step Solution

1. Step 1: Write the proportion equation
   78,815 : 172,942 = 172,942 : x
2. Step 2: Convert to fraction form
   78,815/172,942 = 172,942/x
3. Step 3: Cross multiply
   78,815x = 172,942 × 172,942
4. Step 4: Simplify right side
   78,815x = 29,908,935,364
5. Step 5: Solve for x
   x = 29,908,935,364/78,815
6. Step 6: Final answer
   x = 379,482.78