Finding the Third Proportional to 139.92 and 243.42

Step by Step Solution

1. Step 1: Write the proportion equation
   139.92 : 243.42 = 243.42 : x
2. Step 2: Convert to fraction form
   139.92/243.42 = 243.42/x
3. Step 3: Cross multiply
   139.92x = 243.42 × 243.42
4. Step 4: Simplify right side
   139.92x = 59,254.21
5. Step 5: Solve for x
   x = 59,254.21/139.92
6. Step 6: Final answer
   x = 423.48