Finding the Fourth Proportional to 128.50, 192.76 and 52.50

Step by Step Solution

1. Step 1: Write the proportion equation
   128.50 : 192.76 = 52.50 : x
2. Step 2: Convert to fraction form
   128.50/192.76 = 52.50/x
3. Step 3: Cross multiply
   128.50x = 192.76 × 52.50
4. Step 4: Simplify right side
   128.50x = 10,119.90
5. Step 5: Solve for x
   x = 10,119.90/128.50
6. Step 6: Final answer
   x = 78.75