Finding the Fourth Proportional to 90.91, 136.37 and 42.85

Step by Step Solution

1. Step 1: Write the proportion equation
   90.91 : 136.37 = 42.85 : x
2. Step 2: Convert to fraction form
   90.91/136.37 = 42.85/x
3. Step 3: Cross multiply
   90.91x = 136.37 × 42.85
4. Step 4: Simplify right side
   90.91x = 5,843.45
5. Step 5: Solve for x
   x = 5,843.45/90.91
6. Step 6: Final answer
   x = 64.28