Finding the Fourth Proportional to 75.72, 104.42 and 57.30

Step by Step Solution

1. Step 1: Write the proportion equation
   75.72 : 104.42 = 57.30 : x
2. Step 2: Convert to fraction form
   75.72/104.42 = 57.30/x
3. Step 3: Cross multiply
   75.72x = 104.42 × 57.30
4. Step 4: Simplify right side
   75.72x = 5,983.27
5. Step 5: Solve for x
   x = 5,983.27/75.72
6. Step 6: Final answer
   x = 79.02