Finding the Fourth Proportional to 102.02, 140.72 and 72.86

Step by Step Solution

1. Step 1: Write the proportion equation
   102.02 : 140.72 = 72.86 : x
2. Step 2: Convert to fraction form
   102.02/140.72 = 72.86/x
3. Step 3: Cross multiply
   102.02x = 140.72 × 72.86
4. Step 4: Simplify right side
   102.02x = 10,252.86
5. Step 5: Solve for x
   x = 10,252.86/102.02
6. Step 6: Final answer
   x = 100.50