Finding the Fourth Proportional to 103.98, 143.55 and 72.84

Step by Step Solution

1. Step 1: Write the proportion equation
   103.98 : 143.55 = 72.84 : x
2. Step 2: Convert to fraction form
   103.98/143.55 = 72.84/x
3. Step 3: Cross multiply
   103.98x = 143.55 × 72.84
4. Step 4: Simplify right side
   103.98x = 10,456.18
5. Step 5: Solve for x
   x = 10,456.18/103.98
6. Step 6: Final answer
   x = 100.56