Finding the Fourth Proportional to 91.17, 136.53 and 89.69

Step by Step Solution

1. Step 1: Write the proportion equation
   91.17 : 136.53 = 89.69 : x
2. Step 2: Convert to fraction form
   91.17/136.53 = 89.69/x
3. Step 3: Cross multiply
   91.17x = 136.53 × 89.69
4. Step 4: Simplify right side
   91.17x = 12,244.69
5. Step 5: Solve for x
   x = 12,244.69/91.17
6. Step 6: Final answer
   x = 134.31