Finding the Third Proportional to 17.72 and 42.61

Step by Step Solution

1. Step 1: Write the proportion equation
   17.72 : 42.61 = 42.61 : x
2. Step 2: Convert to fraction form
   17.72/42.61 = 42.61/x
3. Step 3: Cross multiply
   17.72x = 42.61 × 42.61
4. Step 4: Simplify right side
   17.72x = 1,815.56
5. Step 5: Solve for x
   x = 1,815.56/17.72
6. Step 6: Final answer
   x = 102.47