Finding the Fourth Proportional to 105.13, 144.72 and 91.23

Step by Step Solution

1. Step 1: Write the proportion equation
   105.13 : 144.72 = 91.23 : x
2. Step 2: Convert to fraction form
   105.13/144.72 = 91.23/x
3. Step 3: Cross multiply
   105.13x = 144.72 × 91.23
4. Step 4: Simplify right side
   105.13x = 13,202.81
5. Step 5: Solve for x
   x = 13,202.81/105.13
6. Step 6: Final answer
   x = 125.59