Finding the Fourth Proportional to 93.18, 128.69 and 72.71

Step by Step Solution

1. Step 1: Write the proportion equation
   93.18 : 128.69 = 72.71 : x
2. Step 2: Convert to fraction form
   93.18/128.69 = 72.71/x
3. Step 3: Cross multiply
   93.18x = 128.69 × 72.71
4. Step 4: Simplify right side
   93.18x = 9,356.04
5. Step 5: Solve for x
   x = 9,356.04/93.18
6. Step 6: Final answer
   x = 100.41