Finding the Fourth Proportional to 89.99, 134.82 and 72.87

Step by Step Solution

1. Step 1: Write the proportion equation
   89.99 : 134.82 = 72.87 : x
2. Step 2: Convert to fraction form
   89.99/134.82 = 72.87/x
3. Step 3: Cross multiply
   89.99x = 134.82 × 72.87
4. Step 4: Simplify right side
   89.99x = 9,824.33
5. Step 5: Solve for x
   x = 9,824.33/89.99
6. Step 6: Final answer
   x = 109.17