Finding the Fourth Proportional to 200.81, 300.69 and 142.72

Step by Step Solution

1. Step 1: Write the proportion equation
   200.81 : 300.69 = 142.72 : x
2. Step 2: Convert to fraction form
   200.81/300.69 = 142.72/x
3. Step 3: Cross multiply
   200.81x = 300.69 × 142.72
4. Step 4: Simplify right side
   200.81x = 42,914.48
5. Step 5: Solve for x
   x = 42,914.48/200.81
6. Step 6: Final answer
   x = 213.71