Finding the Fourth Proportional to 105.40, 158.01 and 82.50

Step by Step Solution

1. Step 1: Write the proportion equation
   105.40 : 158.01 = 82.50 : x
2. Step 2: Convert to fraction form
   105.40/158.01 = 82.50/x
3. Step 3: Cross multiply
   105.40x = 158.01 × 82.50
4. Step 4: Simplify right side
   105.40x = 13,035.83
5. Step 5: Solve for x
   x = 13,035.83/105.40
6. Step 6: Final answer
   x = 123.68