Finding the Fourth Proportional to 93.05, 128.31 and 72.29

Step by Step Solution

1. Step 1: Write the proportion equation
   93.05 : 128.31 = 72.29 : x
2. Step 2: Convert to fraction form
   93.05/128.31 = 72.29/x
3. Step 3: Cross multiply
   93.05x = 128.31 × 72.29
4. Step 4: Simplify right side
   93.05x = 9,274.89
5. Step 5: Solve for x
   x = 9,274.89/93.05
6. Step 6: Final answer
   x = 99.68