Finding the Fourth Proportional to 72.88, 109.32 and 40.72

Step by Step Solution

1. Step 1: Write the proportion equation
   72.88 : 109.32 = 40.72 : x
2. Step 2: Convert to fraction form
   72.88/109.32 = 40.72/x
3. Step 3: Cross multiply
   72.88x = 109.32 × 40.72
4. Step 4: Simplify right side
   72.88x = 4,451.51
5. Step 5: Solve for x
   x = 4,451.51/72.88
6. Step 6: Final answer
   x = 61.08