Finding the Fourth Proportional to 128.82, 192.82 and 83.21

Step by Step Solution

1. Step 1: Write the proportion equation
   128.82 : 192.82 = 83.21 : x
2. Step 2: Convert to fraction form
   128.82/192.82 = 83.21/x
3. Step 3: Cross multiply
   128.82x = 192.82 × 83.21
4. Step 4: Simplify right side
   128.82x = 16,044.55
5. Step 5: Solve for x
   x = 16,044.55/128.82
6. Step 6: Final answer
   x = 124.55