Finding the Fourth Proportional to 105.83, 158.72 and 54.47

Step by Step Solution

1. Step 1: Write the proportion equation
   105.83 : 158.72 = 54.47 : x
2. Step 2: Convert to fraction form
   105.83/158.72 = 54.47/x
3. Step 3: Cross multiply
   105.83x = 158.72 × 54.47
4. Step 4: Simplify right side
   105.83x = 8,645.31
5. Step 5: Solve for x
   x = 8,645.31/105.83
6. Step 6: Final answer
   x = 81.69