Finding the Fourth Proportional to 90.64, 134.88 and 89.88

Step by Step Solution

1. Step 1: Write the proportion equation
   90.64 : 134.88 = 89.88 : x
2. Step 2: Convert to fraction form
   90.64/134.88 = 89.88/x
3. Step 3: Cross multiply
   90.64x = 134.88 × 89.88
4. Step 4: Simplify right side
   90.64x = 12,123.01
5. Step 5: Solve for x
   x = 12,123.01/90.64
6. Step 6: Final answer
   x = 133.75