Finding the Fourth Proportional to 216.46, 298.72 and 142.72

Step by Step Solution

1. Step 1: Write the proportion equation
   216.46 : 298.72 = 142.72 : x
2. Step 2: Convert to fraction form
   216.46/298.72 = 142.72/x
3. Step 3: Cross multiply
   216.46x = 298.72 × 142.72
4. Step 4: Simplify right side
   216.46x = 42,631.95
5. Step 5: Solve for x
   x = 42,631.95/216.46
6. Step 6: Final answer
   x = 196.95