Finding the Fourth Proportional to 100.16, 138.35 and 72.50

Step by Step Solution

1. Step 1: Write the proportion equation
   100.16 : 138.35 = 72.50 : x
2. Step 2: Convert to fraction form
   100.16/138.35 = 72.50/x
3. Step 3: Cross multiply
   100.16x = 138.35 × 72.50
4. Step 4: Simplify right side
   100.16x = 10,029.32
5. Step 5: Solve for x
   x = 10,029.32/100.16
6. Step 6: Final answer
   x = 100.14