Finding the Fourth Proportional to 89.81, 134.83 and 74.78

Step by Step Solution

1. Step 1: Write the proportion equation
   89.81 : 134.83 = 74.78 : x
2. Step 2: Convert to fraction form
   89.81/134.83 = 74.78/x
3. Step 3: Cross multiply
   89.81x = 134.83 × 74.78
4. Step 4: Simplify right side
   89.81x = 10,082.59
5. Step 5: Solve for x
   x = 10,082.59/89.81
6. Step 6: Final answer
   x = 112.27