Finding the Third Proportional to 78,658 and 171,140

Step by Step Solution

1. Step 1: Write the proportion equation
   78,658 : 171,140 = 171,140 : x
2. Step 2: Convert to fraction form
   78,658/171,140 = 171,140/x
3. Step 3: Cross multiply
   78,658x = 171,140 × 171,140
4. Step 4: Simplify right side
   78,658x = 29,288,899,600
5. Step 5: Solve for x
   x = 29,288,899,600/78,658
6. Step 6: Final answer
   x = 372,357.54