Finding the Fourth Proportional to 91.10, 136.71 and 39.71

Step by Step Solution

1. Step 1: Write the proportion equation
   91.10 : 136.71 = 39.71 : x
2. Step 2: Convert to fraction form
   91.10/136.71 = 39.71/x
3. Step 3: Cross multiply
   91.10x = 136.71 × 39.71
4. Step 4: Simplify right side
   91.10x = 5,428.89
5. Step 5: Solve for x
   x = 5,428.89/91.10
6. Step 6: Final answer
   x = 59.59