Finding the Fourth Proportional to 100.27, 138.31 and 72.56

Step by Step Solution

1. Step 1: Write the proportion equation
   100.27 : 138.31 = 72.56 : x
2. Step 2: Convert to fraction form
   100.27/138.31 = 72.56/x
3. Step 3: Cross multiply
   100.27x = 138.31 × 72.56
4. Step 4: Simplify right side
   100.27x = 10,035.94
5. Step 5: Solve for x
   x = 10,035.94/100.27
6. Step 6: Final answer
   x = 100.09