Finding the Fourth Proportional to 91.32, 136.35 and 89.34

Step by Step Solution

1. Step 1: Write the proportion equation
   91.32 : 136.35 = 89.34 : x
2. Step 2: Convert to fraction form
   91.32/136.35 = 89.34/x
3. Step 3: Cross multiply
   91.32x = 136.35 × 89.34
4. Step 4: Simplify right side
   91.32x = 12,181.51
5. Step 5: Solve for x
   x = 12,181.51/91.32
6. Step 6: Final answer
   x = 133.39