Finding the Fourth Proportional to 91.20, 136.72 and 43.06

Step by Step Solution

1. Step 1: Write the proportion equation
   91.20 : 136.72 = 43.06 : x
2. Step 2: Convert to fraction form
   91.20/136.72 = 43.06/x
3. Step 3: Cross multiply
   91.20x = 136.72 × 43.06
4. Step 4: Simplify right side
   91.20x = 5,887.16
5. Step 5: Solve for x
   x = 5,887.16/91.20
6. Step 6: Final answer
   x = 64.55