Finding the Fourth Proportional to 91.29, 136.87 and 42.57

Step by Step Solution

1. Step 1: Write the proportion equation
   91.29 : 136.87 = 42.57 : x
2. Step 2: Convert to fraction form
   91.29/136.87 = 42.57/x
3. Step 3: Cross multiply
   91.29x = 136.87 × 42.57
4. Step 4: Simplify right side
   91.29x = 5,826.45
5. Step 5: Solve for x
   x = 5,826.45/91.29
6. Step 6: Final answer
   x = 63.82