Finding the Fourth Proportional to 100.73, 139.13 and 72.69

Step by Step Solution

1. Step 1: Write the proportion equation
   100.73 : 139.13 = 72.69 : x
2. Step 2: Convert to fraction form
   100.73/139.13 = 72.69/x
3. Step 3: Cross multiply
   100.73x = 139.13 × 72.69
4. Step 4: Simplify right side
   100.73x = 10,113.36
5. Step 5: Solve for x
   x = 10,113.36/100.73
6. Step 6: Final answer
   x = 100.40