Finding the Fourth Proportional to 105.91, 146.04 and 91.21

Step by Step Solution

1. Step 1: Write the proportion equation
   105.91 : 146.04 = 91.21 : x
2. Step 2: Convert to fraction form
   105.91/146.04 = 91.21/x
3. Step 3: Cross multiply
   105.91x = 146.04 × 91.21
4. Step 4: Simplify right side
   105.91x = 13,320.31
5. Step 5: Solve for x
   x = 13,320.31/105.91
6. Step 6: Final answer
   x = 125.77