Finding the Fourth Proportional to 142.21, 196.02 and 100.67

Step by Step Solution

1. Step 1: Write the proportion equation
   142.21 : 196.02 = 100.67 : x
2. Step 2: Convert to fraction form
   142.21/196.02 = 100.67/x
3. Step 3: Cross multiply
   142.21x = 196.02 × 100.67
4. Step 4: Simplify right side
   142.21x = 19,733.33
5. Step 5: Solve for x
   x = 19,733.33/142.21
6. Step 6: Final answer
   x = 138.76