Finding the Fourth Proportional to 92.50, 138.63 and 72.18

Step by Step Solution

1. Step 1: Write the proportion equation
   92.50 : 138.63 = 72.18 : x
2. Step 2: Convert to fraction form
   92.50/138.63 = 72.18/x
3. Step 3: Cross multiply
   92.50x = 138.63 × 72.18
4. Step 4: Simplify right side
   92.50x = 10,005.62
5. Step 5: Solve for x
   x = 10,005.62/92.50
6. Step 6: Final answer
   x = 108.17