Finding the Fourth Proportional to 89.01, 133.61 and 72.09

Step by Step Solution

1. Step 1: Write the proportion equation
   89.01 : 133.61 = 72.09 : x
2. Step 2: Convert to fraction form
   89.01/133.61 = 72.09/x
3. Step 3: Cross multiply
   89.01x = 133.61 × 72.09
4. Step 4: Simplify right side
   89.01x = 9,631.58
5. Step 5: Solve for x
   x = 9,631.58/89.01
6. Step 6: Final answer
   x = 108.21