Finding the Fourth Proportional to 89.33, 123.39 and 71.91

Step by Step Solution

1. Step 1: Write the proportion equation
   89.33 : 123.39 = 71.91 : x
2. Step 2: Convert to fraction form
   89.33/123.39 = 71.91/x
3. Step 3: Cross multiply
   89.33x = 123.39 × 71.91
4. Step 4: Simplify right side
   89.33x = 8,872.97
5. Step 5: Solve for x
   x = 8,872.97/89.33
6. Step 6: Final answer
   x = 99.33