Finding the Fourth Proportional to 100.29, 138.42 and 72.75

Step by Step Solution

1. Step 1: Write the proportion equation
   100.29 : 138.42 = 72.75 : x
2. Step 2: Convert to fraction form
   100.29/138.42 = 72.75/x
3. Step 3: Cross multiply
   100.29x = 138.42 × 72.75
4. Step 4: Simplify right side
   100.29x = 10,070.06
5. Step 5: Solve for x
   x = 10,070.06/100.29
6. Step 6: Final answer
   x = 100.41