Finding the Fourth Proportional to 57.61, 79.61 and 42.09

Step by Step Solution

1. Step 1: Write the proportion equation
   57.61 : 79.61 = 42.09 : x
2. Step 2: Convert to fraction form
   57.61/79.61 = 42.09/x
3. Step 3: Cross multiply
   57.61x = 79.61 × 42.09
4. Step 4: Simplify right side
   57.61x = 3,350.78
5. Step 5: Solve for x
   x = 3,350.78/57.61
6. Step 6: Final answer
   x = 58.16