Finding the Fourth Proportional to 128.50, 192.89 and 56.41

Step by Step Solution

1. Step 1: Write the proportion equation
   128.50 : 192.89 = 56.41 : x
2. Step 2: Convert to fraction form
   128.50/192.89 = 56.41/x
3. Step 3: Cross multiply
   128.50x = 192.89 × 56.41
4. Step 4: Simplify right side
   128.50x = 10,880.16
5. Step 5: Solve for x
   x = 10,880.16/128.50
6. Step 6: Final answer
   x = 84.67