Finding the Fourth Proportional to 105.18, 144.71 and 102.30

Step by Step Solution

1. Step 1: Write the proportion equation
   105.18 : 144.71 = 102.30 : x
2. Step 2: Convert to fraction form
   105.18/144.71 = 102.30/x
3. Step 3: Cross multiply
   105.18x = 144.71 × 102.30
4. Step 4: Simplify right side
   105.18x = 14,803.32
5. Step 5: Solve for x
   x = 14,803.32/105.18
6. Step 6: Final answer
   x = 140.74