Finding the Fourth Proportional to 56.64, 78.06 and 42.09

Step by Step Solution

1. Step 1: Write the proportion equation
   56.64 : 78.06 = 42.09 : x
2. Step 2: Convert to fraction form
   56.64/78.06 = 42.09/x
3. Step 3: Cross multiply
   56.64x = 78.06 × 42.09
4. Step 4: Simplify right side
   56.64x = 3,285.55
5. Step 5: Solve for x
   x = 3,285.55/56.64
6. Step 6: Final answer
   x = 58.01