Finding the Fourth Proportional to 105.27, 158.06 and 90.98

Step by Step Solution

1. Step 1: Write the proportion equation
   105.27 : 158.06 = 90.98 : x
2. Step 2: Convert to fraction form
   105.27/158.06 = 90.98/x
3. Step 3: Cross multiply
   105.27x = 158.06 × 90.98
4. Step 4: Simplify right side
   105.27x = 14,379.05
5. Step 5: Solve for x
   x = 14,379.05/105.27
6. Step 6: Final answer
   x = 136.59