Finding the Fourth Proportional to 103.72, 155.34 and 100.12

Step by Step Solution

1. Step 1: Write the proportion equation
   103.72 : 155.34 = 100.12 : x
2. Step 2: Convert to fraction form
   103.72/155.34 = 100.12/x
3. Step 3: Cross multiply
   103.72x = 155.34 × 100.12
4. Step 4: Simplify right side
   103.72x = 15,552.64
5. Step 5: Solve for x
   x = 15,552.64/103.72
6. Step 6: Final answer
   x = 149.95