Finding the Fourth Proportional to 89.87, 134.78 and 28.17

Step by Step Solution

1. Step 1: Write the proportion equation
   89.87 : 134.78 = 28.17 : x
2. Step 2: Convert to fraction form
   89.87/134.78 = 28.17/x
3. Step 3: Cross multiply
   89.87x = 134.78 × 28.17
4. Step 4: Simplify right side
   89.87x = 3,796.61
5. Step 5: Solve for x
   x = 3,796.61/89.87
6. Step 6: Final answer
   x = 42.24