Finding the Fourth Proportional to 100.81, 151.20 and 72.06

Step by Step Solution

1. Step 1: Write the proportion equation
   100.81 : 151.20 = 72.06 : x
2. Step 2: Convert to fraction form
   100.81/151.20 = 72.06/x
3. Step 3: Cross multiply
   100.81x = 151.20 × 72.06
4. Step 4: Simplify right side
   100.81x = 10,895.18
5. Step 5: Solve for x
   x = 10,895.18/100.81
6. Step 6: Final answer
   x = 108.07