Finding the Third Proportional to 42,256 and 85,680

Step by Step Solution

1. Step 1: Write the proportion equation
   42,256 : 85,680 = 85,680 : x
2. Step 2: Convert to fraction form
   42,256/85,680 = 85,680/x
3. Step 3: Cross multiply
   42,256x = 85,680 × 85,680
4. Step 4: Simplify right side
   42,256x = 7,341,062,400
5. Step 5: Solve for x
   x = 7,341,062,400/42,256
6. Step 6: Final answer
   x = 173,728.28