Finding the Third Proportional to 42.40 and 72.14

Step by Step Solution

1. Step 1: Write the proportion equation
   42.40 : 72.14 = 72.14 : x
2. Step 2: Convert to fraction form
   42.40/72.14 = 72.14/x
3. Step 3: Cross multiply
   42.40x = 72.14 × 72.14
4. Step 4: Simplify right side
   42.40x = 5,204.27
5. Step 5: Solve for x
   x = 5,204.27/42.40
6. Step 6: Final answer
   x = 122.75