Finding the Fourth Proportional to 105.78, 158.37 and 71.46

Step by Step Solution

1. Step 1: Write the proportion equation
   105.78 : 158.37 = 71.46 : x
2. Step 2: Convert to fraction form
   105.78/158.37 = 71.46/x
3. Step 3: Cross multiply
   105.78x = 158.37 × 71.46
4. Step 4: Simplify right side
   105.78x = 11,317.12
5. Step 5: Solve for x
   x = 11,317.12/105.78
6. Step 6: Final answer
   x = 106.99