Finding the Fourth Proportional to 103.86, 143.52 and 72.81

Step by Step Solution

1. Step 1: Write the proportion equation
   103.86 : 143.52 = 72.81 : x
2. Step 2: Convert to fraction form
   103.86/143.52 = 72.81/x
3. Step 3: Cross multiply
   103.86x = 143.52 × 72.81
4. Step 4: Simplify right side
   103.86x = 10,449.69
5. Step 5: Solve for x
   x = 10,449.69/103.86
6. Step 6: Final answer
   x = 100.61