Finding the Fourth Proportional to 105.39, 158.22 and 91.89

Step by Step Solution

1. Step 1: Write the proportion equation
   105.39 : 158.22 = 91.89 : x
2. Step 2: Convert to fraction form
   105.39/158.22 = 91.89/x
3. Step 3: Cross multiply
   105.39x = 158.22 × 91.89
4. Step 4: Simplify right side
   105.39x = 14,538.84
5. Step 5: Solve for x
   x = 14,538.84/105.39
6. Step 6: Final answer
   x = 137.95