Finding the Third Proportional to 78,890 and 172,396

Step by Step Solution

1. Step 1: Write the proportion equation
   78,890 : 172,396 = 172,396 : x
2. Step 2: Convert to fraction form
   78,890/172,396 = 172,396/x
3. Step 3: Cross multiply
   78,890x = 172,396 × 172,396
4. Step 4: Simplify right side
   78,890x = 29,720,380,816
5. Step 5: Solve for x
   x = 29,720,380,816/78,890
6. Step 6: Final answer
   x = 376,731.92