Finding the Fourth Proportional to 105.98, 158.98 and 45.12

Step by Step Solution

1. Step 1: Write the proportion equation
   105.98 : 158.98 = 45.12 : x
2. Step 2: Convert to fraction form
   105.98/158.98 = 45.12/x
3. Step 3: Cross multiply
   105.98x = 158.98 × 45.12
4. Step 4: Simplify right side
   105.98x = 7,172.55
5. Step 5: Solve for x
   x = 7,172.55/105.98
6. Step 6: Final answer
   x = 67.68