Finding the Fourth Proportional to 109.38, 163.89 and 105.42

Step by Step Solution

1. Step 1: Write the proportion equation
   109.38 : 163.89 = 105.42 : x
2. Step 2: Convert to fraction form
   109.38/163.89 = 105.42/x
3. Step 3: Cross multiply
   109.38x = 163.89 × 105.42
4. Step 4: Simplify right side
   109.38x = 17,277.28
5. Step 5: Solve for x
   x = 17,277.28/109.38
6. Step 6: Final answer
   x = 157.96