Finding the Fourth Proportional to 93.89, 129.69 and 72.17

Step by Step Solution

1. Step 1: Write the proportion equation
   93.89 : 129.69 = 72.17 : x
2. Step 2: Convert to fraction form
   93.89/129.69 = 72.17/x
3. Step 3: Cross multiply
   93.89x = 129.69 × 72.17
4. Step 4: Simplify right side
   93.89x = 9,359.73
5. Step 5: Solve for x
   x = 9,359.73/93.89
6. Step 6: Final answer
   x = 99.69