Finding the Fourth Proportional to 103.84, 142.89 and 100.81

Step by Step Solution

1. Step 1: Write the proportion equation
   103.84 : 142.89 = 100.81 : x
2. Step 2: Convert to fraction form
   103.84/142.89 = 100.81/x
3. Step 3: Cross multiply
   103.84x = 142.89 × 100.81
4. Step 4: Simplify right side
   103.84x = 14,404.74
5. Step 5: Solve for x
   x = 14,404.74/103.84
6. Step 6: Final answer
   x = 138.72