Finding the Fourth Proportional to 90.70, 136.06 and 42.61

Step by Step Solution

1. Step 1: Write the proportion equation
   90.70 : 136.06 = 42.61 : x
2. Step 2: Convert to fraction form
   90.70/136.06 = 42.61/x
3. Step 3: Cross multiply
   90.70x = 136.06 × 42.61
4. Step 4: Simplify right side
   90.70x = 5,797.56
5. Step 5: Solve for x
   x = 5,797.56/90.70
6. Step 6: Final answer
   x = 63.92