Finding the Fourth Proportional to 142.88, 214.24 and 61.72

Step by Step Solution

1. Step 1: Write the proportion equation
   142.88 : 214.24 = 61.72 : x
2. Step 2: Convert to fraction form
   142.88/214.24 = 61.72/x
3. Step 3: Cross multiply
   142.88x = 214.24 × 61.72
4. Step 4: Simplify right side
   142.88x = 13,222.89
5. Step 5: Solve for x
   x = 13,222.89/142.88
6. Step 6: Final answer
   x = 92.55