Finding the Third Proportional to 78,699 and 172,158

Step by Step Solution

1. Step 1: Write the proportion equation
   78,699 : 172,158 = 172,158 : x
2. Step 2: Convert to fraction form
   78,699/172,158 = 172,158/x
3. Step 3: Cross multiply
   78,699x = 172,158 × 172,158
4. Step 4: Simplify right side
   78,699x = 29,638,376,964
5. Step 5: Solve for x
   x = 29,638,376,964/78,699
6. Step 6: Final answer
   x = 376,604.24