Finding the Third Proportional to 42.56 and 74.06

Step by Step Solution

1. Step 1: Write the proportion equation
   42.56 : 74.06 = 74.06 : x
2. Step 2: Convert to fraction form
   42.56/74.06 = 74.06/x
3. Step 3: Cross multiply
   42.56x = 74.06 × 74.06
4. Step 4: Simplify right side
   42.56x = 5,485.25
5. Step 5: Solve for x
   x = 5,485.25/42.56
6. Step 6: Final answer
   x = 128.88