Finding the Fourth Proportional to 100.22, 138.18 and 72.62

Step by Step Solution

1. Step 1: Write the proportion equation
   100.22 : 138.18 = 72.62 : x
2. Step 2: Convert to fraction form
   100.22/138.18 = 72.62/x
3. Step 3: Cross multiply
   100.22x = 138.18 × 72.62
4. Step 4: Simplify right side
   100.22x = 10,034.63
5. Step 5: Solve for x
   x = 10,034.63/100.22
6. Step 6: Final answer
   x = 100.13