Finding the Fourth Proportional to 100.68, 139.05 and 72.33

Step by Step Solution

1. Step 1: Write the proportion equation
   100.68 : 139.05 = 72.33 : x
2. Step 2: Convert to fraction form
   100.68/139.05 = 72.33/x
3. Step 3: Cross multiply
   100.68x = 139.05 × 72.33
4. Step 4: Simplify right side
   100.68x = 10,057.49
5. Step 5: Solve for x
   x = 10,057.49/100.68
6. Step 6: Final answer
   x = 99.90