Finding the Fourth Proportional to 142.80, 215.34 and 141.84

Step by Step Solution

1. Step 1: Write the proportion equation
   142.80 : 215.34 = 141.84 : x
2. Step 2: Convert to fraction form
   142.80/215.34 = 141.84/x
3. Step 3: Cross multiply
   142.80x = 215.34 × 141.84
4. Step 4: Simplify right side
   142.80x = 30,543.83
5. Step 5: Solve for x
   x = 30,543.83/142.80
6. Step 6: Final answer
   x = 213.89